To me it seems the biggest macro factor in your experiments that parallels the decreasing results in quality is the fact that the seasons have changed from warm to cold. Maybe aircrete is just a lot more fickle when it gets cold. And others have pointed out that aircrete by itself is not meant to have a durable surface, nor deal with tensile forces. So for others who are considering aircrete, you'll want to evaluate how it fits into an overall system, and not just how it performs by itself in impact and tensile strength tests. And also re: direct contact with support beam- Any time two different materials come into contact with each other it's good to plan for how they will move differently, and the problems that could cause. With weight bearing aircrete you would probably want to pour a concrete bond beam, or if used for insulation, using a material with some flexibility or elasticity between the aircrete and the solid material.
Yes, the colder temperatures were likely a factor. Drexel says on the label that it should be kept at room temperature. We tried to warm it up some, but I'm pretty sure it was still colder than would have been ideal. These were comparative tests, intended to test the mixtures against each other, also to see if we could get consistent results, and make an aircrete that wasn't overly powdery or brittle.
@@RedandAprilOff-Grid I believe that when using the Drexel foaming agent, it needs stay in the consistent temperature range throughout the curing of your aircrete over several days. The foam will degrade when it is not at optimal temperatures. This will degrade the structural integrity of the aircrete as it cures. Also, the quality of your water is a determining factor. If your water changes in hardness it will affect the longevity of your foam. A shorter foam longevity means that it will collapse before the aircrete has cured. I understand that soft water makes the bubbles last longer. You could try using some water softener salts to see if this makes your foam stronger. But keep in mind that aircrete is never going to be as strong as concrete. Simply put, air is definitely softer than sand. You are replacing sand with air trapped by a foaming agent. Aircrete is more of a replacement for fiberglass insulation. It is not a structural replacement for concrete in a stem wall, or foundation. If used correctly it can add rigidity to a structure and better air sealing compared to fiberglass batting between free-standing / rigid structural members of the building.
From everything I have seen it is certainly more of a wall material than a foundation one. Also the comercial Aircrete blocks are all rather large. They are thicker than cinder blocks, longer and taller. That may have just been that companies being lazy, but I think it does need to be quite a bit more substantial to make up for it's weakness.
You guys made a really good effort and your evidence based approach has been invaluable! Thanks again for sharing the process. I think your decision makes perfect sense.
Yes, we really wanted to make it work, but we just have to cut our losses and move on. The time testing aircrete has been interesting, and while we have been making and testing aircrete the cost of lumber has finally come back down. Red likes working with wood much better than aircrete anyway. OSB was $58 a few months ago, and now it's $21! 😊🏠
@@RedandAprilOff-Grid I have an idea what your issue might have been and two solutions. Besides weighing the foam to check it is the right density, the glycerin separates out and floats on the top of your foaming agent (drexel). This leads to early batches being good and later ones with low to no glycerin where bubbles are weak. The other thing that can make aircrete more stable and more economical and insulative is to add polystyrene filler instead or as well as foam.
@@jonathanberry9502 We added 1 Tablespoon of glycerin to each batch and used a new well mixed bottle of Drexel for our last few batches. My best guess is the cold Drexel was to blame. We tried to keep it warm in our RV, but our RV was still pretty cold. Later we learned that adding warm water to the Drexel may have helped, so that's what we would have tried next.
Batch to batch consistency with aircrete is really hard. Recycled, granulated styrofoam is a great stabilizer. It's free. It keeps EPS out of the landfills, it's bug-proof, and it makes batching your aircrete much easier. You still will have to coat the molded panels with a glass fiber matt. Stucco is a great option for aircrete.
I would have thought that you would stucco over any exposed aircrete to prevent exposure of the elements anyway. Personally I would hard render (stucco) both inside and out. Also I would plaster the inside on top of the stucco for a nicer finish. I have never used or made aircrete. In South Australia they call it hebel, and a factory makes it.
@@nebulousvoid I've built buildings with RASTRA BLOK; which is a Styro and Cement CFS, with 6 inch cores filled with concrete and was pleased with the results. ps. direct flame would not melt the Styro due to it being encased in cement.
“I never lose. I either win or learn.” Nelson Mandela But... learning by mistake is a long and expensive process. Thank you for sharing your experience, good or bad. It sure help other to go faster.
Thanks! Yes it was hard to find good info about making aircrete, or it's long term durability. I watched everything I could find, and messaged a lot of people, but we still had a lot of unanswered questions. Hopefully people can learn from the good and the bad of what we tried. 🌞🏜️
I wouldn't give up on aircrete yet! Regarding the testing of your aircrete block under weights, I feel this is a flaw in understanding the strength of aircrete as the blocks were lacking any reinforcement fabric. You need to use a reinforcement fabric over the surface of aircrete which is what attributes to the strength of the aircrete, as well as the shape of the dome itself, if making a dome structure. The blocks by themselves would undoubtedly crumble due to the porous nature of the material. One simple comparison I can make for this might be to consider a foam poster board. The foam by itself on the back of the board will obviously scratch and puncture easily. With the reinforcement of the poster board with the foam, the entire unit then becomes incredibly strong. That is sort of like how aircrete would work as a structure. You absolutely need the reinforcing fabric to give it its strength.
Yes, aircrete definitely needs to be covered in fabric and plaster. Our testing was to determine if we could make good and consistent aircrete batches, and to compare different recipes. We decided aircrete was not going to be a good fit for our house design. We are continuing to see shrinkage and cracking in the garden wall. Using fully cured blocks would be the only way I would build anything out of aircrete.
Another issue is that concrete is not strong in tension. When you test your blocks by supporting the ends and putting weight in the middle you put the lower side in tension as the block bows. Any concrete will fail like that. Why is this test relevant to your building? Is it so that you can use it as the head of a doorway? Note how the Romans did that as an arch so that every component was in compression.
My experience is that Aircrete is just not great for loadbearing. Good in supplement to more reinforced material, good to work with, but it lacks the strength of other forms. I've only had success when making it in blocks, rather than poured forms but that is probably a matter of operator skill rather than an inherent limitation
Your experiments are a success of what materials not to use in certain circumstances. Thank you so much for you time and effort. One year later and I hope your home is strong and secure with all you need it to be.
Thanks! Yes, just putting it out there for others to learn what they can from it. It was an experience, and made us really appreciate conventional building materials. Our house turned out amazing, thanks!
Yes! Now you are on the right path. No more need to be running test samples for weeks and weeks and getting frustrated. Now you can build and be confident of strength, quality, and durability. Aircrete was very frustrating for me also. I just could not figure out why I could not get repeatable quality aircrete. Cracking and powdering are all issues I encountered. And do you think you can just repair aircrete?...not with the powdering. So glad to see you are moving along with other tried and true methods.
Thanks! Yes, we are so glad to be moving on. We really wanted to make it work and liked it's properties and the idea of doing something different, but it just wasn't working out. The thought of having the inside of the walls eventually turn to powder, was looking like a real possibility. If we could have made batches like the first ones every time, we would have went ahead with it. I'm pretty sure the cold temperatures were not helping anything, but I also wonder about the Drexel. As other channels have mentioned, it seems like the first batches with a new jug turn out awesome, and the last batches turn out terrible. So, when we opened a new jug and mixed it well it just mixes the good and bad parts of the Drexel together. Then we had batches that didn't fall, but also weren't great quality, because they had the grainy stuff mixed in from the bottom of the jug. 🤷 Just one more idea of something else that might have contributed.
@@zacwhiting1563 Hello Zac, It is on a long-term hold. Like so many other people, Covid-19 and job(employment) problems have kept us from our home on the island. We are hopeful that things will get back to normal soon. In the meantime, I am tinkering with a Tri-Magnum build. I may put some videos out on this.
@@paulwyleciol3459 No we just used Drexel. Suave Clarifying Shampoo looks like it might be a good option, but you need to use a lot of it so Drexel ends up being less expensive. Maybe some of the other types of soaps do better with cold temperatures. It's worth a try.
I just wish you guys all success. I know what it's like to have to make radical course changes during a project. It always hurts. But, life itself is really a grand collection of lessons learned.
one way to make it more consistent with its strength and also to improve thermal resistance is adding styrofoam to your aircrete mixture, a lot more thermal resistance and the strength of it is still very good, the only issue is it'll flake against the elements. you need to wrap it with fibermesh then stucco it or like Stephen Williams stucco+limestone. you can find a bunch of neat videos from Stephen Williams on how he built his work shed with it as well as an arched gardenshed now.
Styrocrete looks like quite the process. We personally weren't interested in driving all over town trying to find styrofoam. We don't live by a large town, & we would need a whole lot to build a house. I know it's all the rage right now, so we should be seeing styrocrete structures popping up everywhere soon. It will be interesting to see how it works out for people. 🙂🏡
Congrats. You all weren't completely deceived by crap on social media. Social media is all about getting viewers...not valid info. It's full of many things that makes people wonder "why aren't all homes built this way". There's always a reason.
Let me start by saying, thank you for the awesome video! We need more of us!! However, I'm not sure I agree with your statement that you've "controlled the condition." You never developed a real consistent process. You changed the formula half a dozen times over no more than two dozen batches. You did not measure temperature of the material or ambient temperature for your cure. and as you mentioned you don't seem to have used the same mixing times. Cement is very sensitive to ambient moister and temperature as it cures; mixing time (adding heat into the cement) can also effect cure times. Add to that the fact that the foam is going to loose structure the longer the cement stays open, means you're definitely going to have inconsistency no matter how well you control. I've made about three batches using the same Domegaia set (the newer Dragon XL version). The discrepancy (I believe as I've observed) is due to the fact that the author of the material built these domes in climates which stay stable, well within the cure range of Portland cement. Your place looks like our. COLD! Which means we're going to have huge fluctuations in temp thought the cure process, making it seem like we're not locking in some other factor. IE Did you start every batch at the same time of day, and where they exposed to the same ambient conditions. A really good control (which I need to do if I'm going to cure in the dead of winter) is to enclose the forms in a temperature controlled enclosure, that could keep a nice consistent 60F (the optimal cure temp for Portland cement). The ASTM compression test, uses a hydraulic press with a pressure gauge to test for compressive loads on cylindrical core sample size. The method you used is excellent when considering whether to use this for a lintel or to span an area (which aircrete is not for), it does not inform much as to how much actual compressive strength is available in the final monolithic structure. Adobe only provides about +300 PSI. CEB provides well over 3000PSI. aircrete falls closer to adobe, but still has more than enough strength (even your worst batch, maybe not the cellulose added one) to build a 10 foot wall that is 12 inches deep (no load). Compressive strength is very different than tensile strength. Though aircrete is brittle, and does not have the same tensile or compressive strengths of concrete, it has a very high compressive to weight ratio, which makes it ideal for small structures such as domes and arches where the nature of the structure itself provides load mitigation, and where you're not exceeding the load limits. You can build very strong arches (especially Catenary arch) and domes with the stuff. Most of the materials (even what you would consider failures) can be used in a dome with re-enforcing fabric, and once you have the scratch coat and the finish on it, despite the lack of tensile strength (increased by the wrapping fabric), you now have a strong monolithic structure. Resistant to wind and weather, with far better insulation factors than any conventional frame house you could build, and in the process building an environmentally friendly and cost effective home. I can certainly understand the time constraint, that is a different story. I'm sleeping in a tent, in the dead of winter, build on our property; and as crazy as I am in loving every minute of it, I certainly can't expect my better half to be able to withstand it. So I think your conclusions on aircrete are possibly driven by other factors and not aircrete itself. The inconsistency is not in the product, it is the way in which we (you and I) are producing it, all of my problems with it so far, have been basically self induced.
Yes, based on other aircrete channels we were watching, we knew it was going to be difficult to get a consistent product, but it was even more challenging than we expected. We started at about the same time of day for all of our batches. With the first samples were made in the afternoon, we were in the low 80s and ended up pretty close to freezing every night. We were expecting to be able to make aircrete through most of the winter, but our particular location is often 20° degrees colder than the surrounding towns. So that was a huge bummer. Yes, I think the cold Drexel was likely our main issue after the first batches. Also, if the first part of the jug makes awesome aircrete, and the second half of the jug doesn't work at all, what does that say about Drexel? Harry showed it keeps it's volume way more than other foaming solutions, but what he didn't show, was the large amount of water in the bottom. We are living in an RV and doing everything on solar, so there wasn't any great way to keep the Drexel at room temperature, or to heat the water. That may have been the issue, but the problem of cold wouldn't have gone away until well into spring, and in the spring we get consistent dry winds, which would have made curing an upright wall extremely difficult. If we could have got successful batches in the fall, we would have been encouraged to continue, but if it's that temperature sensitive, we we decided it just wasn't going to work for us. Best wishes, I do think it can be done, we just don't want to spend years trying to get it to work, and we don't know enough about the long term durability of the aircrete. We could imagine it eventually turning into powder inside the walls. It will be interesting to see how the garden wall looks in a few more years. The tests we did were to compare the different samples to each other in a fairly consistent way.
Was it by any chance cooler and more humid with those successful tests? I learned if any concrete dries too fast, it cracks and crumbles...or was the heat and humidity the same during pours? I know you've moved on, but would love to know if it's worth it to invest in a hopper that measures those variables in it's mixture ratios so the batches all come out the same. Super important when needing to make a consistent mortar, too, so the walls don't crumble later if they cure at different rates and contract/collapse. Thanks so much for sharing your efforts!
We figured as long as the temperatures were staying above freezing it would be okay. I think by the end, it was getting too cold. The well water was cold, and the Drexel was too cold. Now people seem to be saying if you add warm water to the soap solution, that should fix the problem. Which would not have been practical for us since we are off the grid and running everything on solar. We didn't realize temperature was such an issue, our 100°+ summers probably would have caused issues too. Measuring the materials wasn't difficult, but mixing them together really well was. We were planning to buy a mortar mixer, and sell it after we got done. There are so many reasons we are glad we didn't build with aircrete. Leaking forms, shrinkage, cracking, labor, cost, cure time. We found the whole thing to be a big pain. It's also unknown how long an aircrete structure will last, and I think there are better building material options out there. Aircrete is an interesting material though, and I'm sure it can be done. Best wishes! 🌞
Sorry to hear the original plan wasn't working. Thanks for sharing your experience though. That is really good info to know. Looking forward to seeing the rest of the build.
Thanks! It was a learning experience for sure, and we are excited to get back to work building the house. Our first delivery of materials is set to come on Wednesday. 😊🏠
@@RedandAprilOff-Grid Testing batches was very smart! Most people would slop it together and worry later. I’m glad time and common sense was on your side.
Thank you for sharing. Comerciallly, aircrete is cured in a controlled environment and the bubbles are produced by a chemical reaction that can be controlled by recipe. This is the difference between CLC (what you have made) and AAC (commercially made). AAC is cured in a temperature controlled pressurized oven. I’m sure your results can be attributed to the cement moisture exposure prior to curing or temperature/pressure changes with weather. That’s my guess anyway.
Thanks for watching! There is a lot that can go wrong with homemade foam aircrete. The colder temperatures were probably a contributing factor too. Glad the prices on materials went down, and we were able to build our house through the winter. Glad we didn't wait until spring.
@@WubiWatkins The temperatures were in the low 80s when we were making the first batches, and mid to low 70s for the later one's. It was getting down below freezing at night for our last batches, so we had to keep the last set of samples in the well house to keep them from freezing. The foaming agent Drexel also needs to be kept at room temperature, and it was likely too cold. Adding warm water to the soap solution might have helped.
How long have you had that cement powder? It has a shelf life. After three or so months it is starting to absorb enough moisture from the environment to significantly affect its strength. Obviously that number is affected by how well it is stored and the humidity in the area, but as a rule of thumb...
It was purchased within a few weeks of using it. There was a shortage in the stores when we were trying to make these samples, so we tried a few different types.
Adding fiberglass might help with strength and structure... I did notice that you had a bunch of bags of quickrete... that may affect your batch consistency once you bring the bags home and let them sit outside they can lose quality fast
I applaud the time and effort you put into your Air-Crete investigation. Glad to see you are moving on. Lessons learned in a controlled environment as opposed to potential consequences down the road.
Thanks! Aircrete is interesting stuff, and I'm glad we were able to share our experiences. People may decide it's not for them, or they may see ways to make it better. A plus for us is that while we were making aircrete, the price of lumber went down. We are excited to start building our house! 😊🏠
You were so methodical in your aircrete attempt I thought if anybody could do it you would. The alternative to aircrete that I thought was most promising was using ground up expanded polystyrene packing instead of foam. It comes out very fireproof, fairly strong and good insulation. The biggest advantage is consistency without having to rely on foam. There is a company in Phoenix that makes blocks of this material which stack together like Legos and then concrete is poured through the openings to lock them all together. The walls still have good insulation. Another guy on RUclips built a garage using ground-up polystyrene and cement mixture for the walls and he even tamped them from the top as he was pouring . He then built a second story on the garage to prove the walls were strong. Supposedly you can get the polystyrene packing from furniture stores etc and save it from ending up in the landfill. But you still have to go to the trouble to grind it up.
Yes! Agreed! Also when 3m was forced to change the formula on styrofoam it's only the glue that is flamable. Once it's shredded, it won't burn. Silicone foam is flame-retardant, self-extinguishing & can withstand 2100 degrees F flame for more than 10 minutes without burning. I was shocked when I tried it myself. Also the silicone foam and AirCrete mixture is what's currently being used in Asia for home building , yes, even on load bearing walls.
just to be clear the guy who made the garage was using AIRcrete with styrofoam which is differtnet than EPSCrete which is just normal cement and styrafoam. ruclips.net/video/6U4JAop0dTY/видео.html
@@khandam7709 I just watched the video again and you are right, he mixed aircrete with what he called styrofoam. What he calls styrofoam is actually expanded polystyrene beads (the most common packaging material, commonly ending up in landfills because it can't be recycled easily like a lot of plastics). Since he tamps this mixture in the walls he can't be thinking that the bubbles of the foam are being retained, can he? He claims the aircrete is just acting as glue for his styrofoam. Why would mixing foam with the cement make it any better glue? @4:18 ruclips.net/video/27v7Oq-q9xs/видео.html&ab_channel=StephenWilliams
As someone whose only experience with air crete is “I watched a few videos,” I would just add that some claim to get better results with foam crete, using a soap-based foaming agent to “fluff” the mix. I should add these videos were made by people who were promoting/selling the idea of foam Crete, so of course they may not be the most unbiased source, but a suggestion if still considering. I applaud you for trying this build, and doing so very reasonably and methodically.
Thanks! Yes, this is soap based aircrete, with Drexel as the foaming agent. My best guess is that the Drexel was getting too cold, & our night time temperatures were starting to get below freezing. We kept the samples wet and protected from freezing but it still wasn't ideal for the curing process. Aircrete is tricky stuff. I assume the hot summer temperatures wouldn't have worked well either.
Thank you so much! The videos and experiments you made will be of great service and value to many others, so please don't feel your work has been a waste. And if i might ask- many of us would be interested to see an update on the garden wall in the spring or in a year. (And if you have space to keep the samples, maybe evaluate them once they've all had a chance to fully cure and age a bit. I have a feeling a few of them might behave differently after several months)
It was an interesting experience, and I'm glad we were able to make videos that others can learn from, even if it's just so they can see what we are doing wrong and figure out how to make it better. We are mostly just relieved we won't have to deal with some of the challenges and uncertainties of trying to make aircrete work, and we are excited to start building our house. Red likes working with wood better anyway, and the prices have finally gone down. 😊🏠
Yes, we plan to show the upcoming progress on the garden wall. We also plan to build an outdoor rocket mass type stove, and maybe a pizza oven with some of the larger aircrete sample pieces.
A bit of summary for my own brain. 😆 (some of my own thoughts included) - while air Crete is a cool material, and someone else might be able to build a house with it, it wasn’t a good fit in this situation for full-wall construction due to batch consistency, compressive weakness, powdering, and microcracks. - difficulty with overall mix consistency despite increased efforts to control for all possible variables. Inconsistency carries the risk of having some good spots and some bad spots in the same structure and even the same wall. - bubble size, issues with large bubbles despite trying additives and nailing down density/quantity. Same risk as with overall consistency. - micro cracks on the surface even in fiber reinforces mixes indicates a risk of long term surface weakness/ potential spalling. Even with surface bonding cement, if the outer layer is weak it can spall. This risk might be ok for a shed but not for a long term residence. - it’s tendency to powder/give way with light pressure is incompatible with the need for lateral support of the metal posts against twisting and bowing. - erratic/low tensile strength carries the risk of exterior wall panel failure in the case of high wind gusts and other weather impacts.
My own take away, is that aircrete is a decent insulator, resists pests and especially wood eating insects, but is not structural and should be treated like an insulative material (like rigid foam or rock wool) This matches what I have concluded from aircrete experiments by others. If this conclusion turns out to be accurate, then increasing the insulative capacity instead of the strength capacity makes a lot of sense.
The lighter mixes are just so weak and crumbly. I'm not sure how well they would hold up even inside a wall, especially if the wall gets any kind of vibration or impact. The stronger mixes are much less prone to crumble or turn to powder. Our strongest mixes probably would crack, but I don't think they would turn to powder like the lighter samples that had bigger air pockets.
We let the samples wet cure for 7 days. We knew there wasn't any way we could keep our house walls wet for 30 days, and it was a comparative test between the different mixes. We also tested the samples dry a month or so later.
Aircrete is meant to be built with self reinforcing geometries like domes and arches, just like Roman concrete, then encapsulated on both sides with fiberglass or basalt mesh. When it is kept under compression and encapsulated with these tensile layers it is strong enough to even be earth buried. Straight walls are not recommended. Good luck with your build.
I'm sure Roman concrete was much stronger than this stuff. Aircrete is a whole different thing and has way less tensile and compressive strength than any type of concrete. Plaster would help, but with pressure, our samples compress down and turn into powder. Thanks! We are excited to get this house built. 🙂🏠
@@RedandAprilOff-Grid Indeed. It is 70% air after all. It was never meant to pass the tests that this channel put it through. Neither would styrofoam, another product that is mostly air. The benefit of Aircrete is that it can be created from scratch, formed easily, manipulated very easily, insulates well, is fire proof, rot proof, bug proof, and water retardant. Making long blocks then placing weights in the middle to test its tensile strength is the opposite of what it is good at. Pressing direct pressure over a small, localized space to test for compression, is not what it is good at. Aircrete is a lattice of cement bonded around air bubble geometries. It distributes loads well. When Aircrete is spanned across a distance, stacked in an arch or otherwise round shape, encapsulated in an exoskeleton of tensile reinforcing mesh and finished with stucco, it can hold tremendous weight. This is why Domes built in this manner work so well because their geometry works well at distributing loads across the cement air bubble lattice of the Aircrete while the tensile exoskeletal layers prevent outward expansion and lateral shearing. I can poke a hole in raw Aircrete with my finger, and I can also drive a car on top of an Aircrete Dome after the tensile layers have been added while the inhabitants of that dome stay warm inside due to its rigid insulation properties while it is retaining a hillside and terracing land as it is partially earth buried.
@@WhistleLad The purpose of our testing was: to get a feel for aircrete and the process of making it, to compare the different mixes to each other so we could decide which recipe we wanted to use, and to see if we could produce a consistent and reasonably strong aircrete that wasn't overly brittle. We aren't saying it can't be done, but we were not able to do it, and have seen many others struggle with making it themselves too. It sounds like someone has figured out how to make some good and consistent aircrete, that sounds like an amazing dome. 👍🙂
@@RedandAprilOff-Grid I am suggesting that Aircrete is always brittle and that there is no way to change that because it is 70% air. The brittle factor can be reduced, but only at the expense of the air. More durable Aircrete will inevitably have less air bubbles in it, which will reduce its insulating properties. Different mixes serve different purposes and there are nearly an unlimited number of mixes that can be produced. Fiberglass or basalt chopped fibers can be mixed in, thickening agent and air entrainment can be introduced, but the end result will always be somewhat weak when the air ratio is >50%. All of the blocks I make are brittle, but when they are stacked like an igloo and the dome walls of Aircrete are sandwiched between tensile reinforcement layers like basalt mesh the whole structure becomes incredibly strong. The blocks themselves do not need to have tensile strength, nor shear strength, nor localized poking strength because they cannot move once within the outer shell of the mortared on reinforcement layers (basalt or fiberglass mesh) and because those tensile layers transfer loads down the geometry of the structure in a distributive way. Surf boards 🏄♂️ are made of styrofoam a very brittle and easy to poke-thru substance, however, once the fiberglass resin layers are added to the exterior, surf boards 🏄♀️ become strong and durable. This is similar to how Aircrete is best used. I am primarily explaining this for anyone who will read the comments. I understand that for your build you have now chosen a material that is better suited for your plans. Sending you best wishes. We will each be in new homes very soon! Round or rectangular, home is where the heart is.
Yes, poured concrete is a great way to go. We considered it but decided we wanted more insulation, but with our overhangs and orientation I think it would have worked out pretty well. 🌞
Yes, our supports were going to be 8 feet apart, so we were a bit worried about the aircrete having to span that large of a gap. Some of our batches were pretty nice and not powdery and brittle. The cold Drexel was likely a contributor to the issues with the later batches.
Aircrete is not good for load bearing unless the bricks are at least 12" ×12"×18". The best way to use it is within structural panels to serve as insulation. That's what seems to work the best. It can be used for domes because that shape is "self supporting".
Thanks for documenting this so others will know to not rely on aircrete as structural elements. This is why others use more structurally sound elements within or around the aircrete to compensate. Personally I think such compensations make aircrete a superior solution but your pivot worked well. Well done.
I think it would be well worth your while to attend an aircrete workshop. I know both 'Aircrete Harry' and 'Domegaia' put these on. Harry also does consulting work at a very reasonable price. If you watch his videos, you'll see he went through all your issues and he has shown how he overcame them.
The workshops are pretty expensive. I also figure that a lot of the people who go through the workshops decide not to use aircrete, I'm just not seeing many people actually make or live in anything made out of aircrete. I watched most of aircrete Harry's videos, and anyone else talking about aircrete that I could find. I ordered Harry's thickening agent, and asked him some questions. He didn't answer my questions about how to get soft water, but we found an RV water softener that worked well. Giggedy George finally did a video detailing, what our main problem probably was, but by then it was too late. Our batches got worse as the temperatures dropped, it appears that using warm water in the Drexel solution likely would have helped. We have videos showing everything we tried. We had some great batches in the beginning, and go into foam density and other issues we dealt with in detail.
@@RedandAprilOff-Grid I think you were likely up against a few different things. I don't put a lot of stock into Quickcrete products. I watched another guy doing aircrete and he was using Bluebell or something then one time he got some Quickcrete and it was a disaster. The temperature is a huge factor too. Then even if everything goes right aircrete is still aircrete.
I can tell you exactly what you did wrong as far as the consistency of the aircrete is concerned. This is a mistake many make including me,very frustrating, so don't feel alone. Ignorance is NOT stupidity. The first time you start making aircrete there is a hesentincy to the mixing. As you do more, you naturally mix faster. To keep the small tight bubbles, foam size, it is extremely important that you mix at a very slow rate. Moving up and down, side to side. Never allowing the whirlpool effect to carry air into the mix. Mixing to fast also causes the foam to combine into larger bubbles and when taken to extreme the air crete will collapse during the curing. This is obvious when I watched this video and saw how the progression of the old to new bricks where laid out. #2 The plans for your house are for the most part conventional. Aircrete in this case is only good as an insulator, not a structure. So you made the correct call changing your plans. Beyond what I have to say you guys presented a awesome video of your experiences and I learned from it. Thank you so much for posting!
Aircrete is very finicky stuff, glad you figured out what worked. We tried all different types of mixing strategies, which can be seen in our other videos. I suspect that the cold Drexel was the problem with our later batches, but mixing speed may have contributed too. Best wishes on your aircrete projects! 🙂
Sorry for your frustrations! I just came across this video and I am WAY late to the party. Haven’t read the comments from others. Just wanted to offer some information I learned some years ago when I was sold on rammed earth: it’s a method called PISE which is the acronym for “pneumatically impacted stabilized earth.” The system utilizes sheet goods (kind of needs to be plywood) as an inside-of-wall form against which is shot resident soil mixed with Portland cement and fiberglass shards and applied with a gunnite machine which introduced water at the nozzle. I saw a residence and a winery office building done this way in Northern California and it actually passed building code with the addition of some rebar which the builder told me was totally unnecessary, but required here in earthquake country.
Sounds cool! Yes, once we couldn't find a tractor for a reasonable price, we backed out of rammed earth and decided to try aircrete, and when that didn't work, we went with wood and metal as the main materials for our DIY home build. 🏠🏜️
Red and April thank you for sharing your "real" journey. By you sharing your data and your outcomes (good and bad) is like learning right alongside you. --So, as you have proven, Aircrete created with "foam" (foamcrete as I call it) is very fragile. It has its use in certain geodesic forms or non-domiciled structures, and hardfacing helps stability some (Honey Do Carpenter/The Happy Heresiarch) - but you really need chemically generated air bubbles for consistency and autoclaving to make aircrete somewhat durable. (Autoclaved Aerated Concrete = AAC - Think Hebel or Aercon AAC Blocks) But DIY'ing AAC is prohibitively expensive - as autoclaves are. And purchasing AAC is also expensive and defeats the goal of self-sufficiency, IMHO. You folks seem as if you've done your research, so I assume you know how extremely labor-intensive rammed earth really is. --So my question to you is before you move on to rammed earth, had you considered these two alternatives? --1) Creating polystyrene/cement blocks or panels instead of foamcrete? You may be able to create more durable blocks/panels for the walls in your home, that perform just as good - if not better than aircrete, simply by using recycled ground-up polystyrene beads and Portland cement with an ad-mix. (Think "The Perfect Block" out of Tucson - but without holes or need for the expensive grouting) Structural support would still come from your steel frame. Stephen Williams (Aircrete) - has a RUclips channel where he's built a structure in this manner. --2) If you like the thought of truly using "earth" as the building material, had you considered compressed earth block for your home? It's still labor intensive but less so than rammed earth and it produces similar look/performance of rammed earth. "Sustainable Living" RUclips Channel
We gave it a good go, but aircrete is tricky stuff! We steered away from rammed earth because of the equipment needed, labor, and we wanted something that would be more insulative. Styrocrete looks interesting, but it is also untested, and looks pretty labor intensive and messy. Even if it's easy to shred, that's a whole lot of styrofoam to collect and deal with. We decided to go with a more traditional build, and found it won't cost us any more than aircrete, and it is going up much faster. I just found your comment, sorry about the delay in responding. 🙂
@@RedandAprilOff-Grid im sure you know that cement cures through hydrolysis. Heat can speed up curing. But you need water. Too much water and your product can be weak, to little it never cures. You are very correct its hard to get consistent results as their are so many things out of your control. The humidity, heat, sun light, wind, other convection. Great luck in the future. Its better to get something done poorly then to keep thinking and never start it.
Thanks! We had a really hard time finding answers to our aircrete questions, so we wanted to put it all out there for others to learn from. The good and the bad.
Perhaps aircrete is more suitable as an insulation material and not rely on structural capability at all. It looks like your cement dried out too quickly, thats why the blocks are powdery, cement needs moisture for a few days to chemically cure.
When testing our first set of samples we watered them twice a day for 7 days. These last fiber samples were not kept as wet in the well house. They were just covered in plastic, which kept quite a bit of the moisture in but not as good as daily waterings. We could also tell right away that the samples had large bubbles and were more like our number 3 and 5 batches, so we weren't expecting great things out of them. Samples 3 and 5 we're also quite brittle because of the larger air pockets, even though they were cured properly. It might work okay for insulation, but the lighter mixes turn to powder with any rubbing or impact.
@@RedandAprilOff-Grid given all the headaches of foam with aircrete it's easier to use styrofoam which is easily gotten in larger cities and has R value of R2.5 vs 2.2 for air crete ruclips.net/video/6U4JAop0dTY/видео.html
@@khandam7709 It would require a whole lot of styrofoam, and I'm not sure that it's actually that easy to make or dependable in how it turns out. It will be interesting when more people start making stuff out of it and showing their results. We are not near a big city, don't have a big shop to store and shred massive amounts of styrofoam, and I would rather not have our vehicle and property covered in styrofoam bits.
@@RedandAprilOff-Grid You are very thorough in your experiments. The only other thing I could think of to improve the blocks would be to line each block mold with a sheet of housewrap or similar material so that you get the effect of drywall, as the plaster powder in drywall is very brittle and requires the paper both sides to give it strength. Maybe other fabrics would work, if they are able to hold moisture and not shed it like housewrap it could be dipped in a bonding agent to help glue it to the block, but then your mold would have to be polycarb or some other rigid plastc, and the blocks would have to be big in order to make it worthwhile to go to all that trouble. Going for a coating solution rather than an additive could work out cheaper than mixing a substance all the way through when just strengthening the outside of the block is required.
So , have you ever changed the formula? I just watched it on RUclips, they use very small amounts of cement. They produce it with a large amount of lime and much thicker than this.
Graphene-enhanced concrete is tested and it provides a 146% increase in compressive strength, a 70% increase in flexural strength, and a 400% decrease in permeability. The incorporation of graphene in concrete would develop structures with increased durability, an increased conductivity, and thermal properties. Resulting in an overall decrease in CO2 emissions. Hemp concrete or hemp lime, it's a biocomposite made from a mix of the woody core of the hemp plant, lime binder, and water. The hemp core (also hemp hurd or shiv) has a high silica content that allows it to strongly bind with the lime.. As a result, you get a lightweight, cementitious material with good high insulation properties that weighs six to eight times less than concrete. It's ability to aborb CO2 emissions actually make it a carbon negative product. Because of the high moisture content care must be taken in the drying or curing of hemp, unless your intention is to make hemp graphene. At this time hemp is available in moderate amounts except for industrial or textile use and is utilized in a variety of products from clothing and shoes to bulletproof vests, car parts, artesian niche soaps, oils, beauty and health products. For hundreds of years it has been available as rope for maritime travel in boats and netting. Hemp as a means of paper and due to it's strength even the paper is utilzed to make implements, dishes, cups and musical instruments. Aircrete is simply concrete with bubbles., there is no set formula. Fine foam, which has a high density, can be added to increase aerated concrete's strength, which results in a stronger aircrete. When high densities of foam are included, aircrete can become brittle, and chipping can occur. This type of aircrete will have limited compressive strength and could not be load-bearing.Aircrete offers many traditional concrete benefits with added properties to enhance sustainable and energy-efficient homes. Aircrete offers superior insulation properties due to foam and air bubbles built into concrete itself which can be enhanced by adding various types of polystyrene or polyurethane foams improving it's insulation values.Aircrete is most often used for exterior and interior walls. However, aircrete can also be used for several other home applications, such as precast blocks and panels and concrete slabs for an insulated flooring system. In some cases aircrete is used for poured roofs, increasing insulation capacity of ceilings and attics where heat tends to escape from homes. When used with additives it's load bearing capabiities, compressive strength, durabilities and other characteristics are greatly enhanced.
The availability, cost, and labor of different aircrete add-ins was our main consideration. I have seen people experimenting with using graphine in aircrete, but it seems to be hard to get in a usable and affordable form. Adding styrofoam looks interesting, but the logistics, method, and tremendous amount of space and styrofoam that would be required to build a home are a couple of things that steered us away from it. Red adjusted the air pressure some for the colder temperatures, but I think our foam was still more dense than it was earlier so I figure that's why our batches were getting more brittle. Now that the cost of lumber has come down some, it is actually less expensive to build a more traditional house than one out of aircrete. Aircrete would have made a more interesting house, but we didn't want to wait 5 months before we could try again. Good info! 😎👍
@@RedandAprilOff-Grid it's cheap to make graphene and it can be made from most anything including sugar. Aluminum powder limestone powder and polystyrene is cheap.Basic recipe for non-autoclaved lightweight aerated concrete (aircrete) with 600lbs kg/m3 density: -Ordinary Portland cement -Limestone powder (particles up to 0.05 mm) -Aluminum powder MEPCO 7520 or any Aluminum powder with blaine value 15,000 cm2/g and more Dry mix formula: 50% cement (by weight) + 50% limestone powder. For 1 kg of dry mix you need 500g cement and 500g limestone powder Mixture formula for for 700kg/m3 density: 1 kg of dry mix0.65 liters of water, 1 g of aluminum powder for 100 kg of dry mix you will 65 liters of water and 100 g of aluminum powder. How to mix it: 1. Add water in the bucket. 2. Add dry mix in the water and mix it for a couple of minutes. 3. Add aluminum powder and mix 1-2 minutes. 4. Check video for graphene dry mix ratio and add 5. Pour in mold. Videos are on RUclips.
Did you use a good quality former with a professional grade foaming agent? Measured by weight? I have never seen such quality deviations like you had. What did you use? Dish soap?
Question . How long did you let it cure ? You have to let it sit for 28 days to fully cure . And it's best to keep it wet . And shaded . Harsh sun will burn green Crete . Making it powder .
Thank you for showing the reality of aircrete. I commented in your other video that I used perlite, it is rock bubbles so there is no inconsistency in the air bubbles because they are already bubbles incased in rock when you get the perlite. I also sandwiched the lightweight concrete with fiber stucco to give it hard surface. Where are you located that you can do builds like this? Rural Texas? I will also say if you are willing to spend lots and lots of time building, they are many options. My idea was a method that is not labor intensive, but only time intensive using forms to create arches. You can only pour one arch at a time, and then wait days for it to harden enough to do the next one, and 50 arches then takes a long time....but not a lot of labor, and it would scale if you have multiple forms.
We are in Cochise County, Arizona and have an owner builder opt out permit, so we thought it would be fun to try something different. It was an experience and made us appreciated regular construction materials even more. We liked the idea of just adding bubbles, because it would be less materials to buy and deal with. We were so glad, we changed plans, and love that our house is very energy efficient, and almost completely passive. The arches sound pretty cool! 👍🌞
Thanks for sharing your experience. Perhaps it is not meant to have supporting features, as columns or beams, Perhaps to be used on the floor only, as screed? Would you agree?
Aircrete does not have good compressive strength and needs to be supported, which also makes it not good for floors. There are cheaper and much easier ways to insulate a floor or walls. We insulated our earthen and concrete floors with rigid foam board.
Is this not the same as foamcrete? Where the use of dish soap is applied. That is to say, are the two dishcrete enough in significance to merit speaking of in different ways? Harhar.
It sucks to invest time and money in a building system only to have to abandon it. Hopefully your experience will spare others from that experience. Thanks for sharing!
Most intriguing, I’ve made a hundred honey bee boxes from aircrete but mixed with sheep wool for humidity regulation, but this was done by a pro with my moulds and I finished them of with micro cement
2:05 I am not a fan of aircrete. But this is clearly user error. All concrete has low tensile strength and high compression strength. That test is for tensile strength. Either reinforce it or use a different material for the parts of the house where you need tensile strength.
The testing was to compare the samples and different recipes against each other, as well as our ability to make good consistent batches, to determine if we wanted to build our house out of it. We were definitely going to reinforce it, this was just one video in the series.
Sorry it didn't work out after all your effort. Was wondering if you did anything to your foam gun like seeing if the stainless steel scrubbers were compressed?
Thanks, no we haven't looked at it. The temperatures were starting to get below freezing, so we figure that was probably a factor. Aircrete would have been such a pain, I'm really glad we didn't try to use it.
You folks are an inspiration. I have been testing mixes of portand cement and native soil here. I have found a 3/1 mix of screened soil is really good stuff here. Thanks!
Awesome! We were considering trying to make a batch with dirt, but our soil varies widely. We have it all, silt, clay and sand, so we figured it would be hard to get a consistent product since we would need a lot. Sifting the sand through a fine mesh for our test batch was sure was a lot of work, but it did make a good strong aircrete. Thanks for watching! 😊
I think the colder temperatures were likely contributing to the issues with the later batches, but there may have been other factors too which just makes aircrete overall not a good option for us out here in the desert. We have big temperature swings from day to night, and are typically very dry. We kept the samples covered and watered them twice a day, but not much else we could do to control the environment.
did you add metal reinforcement rebar/Concrete Remesh in the mold/forms? also did you vibrate or hit the outside of the forms to get the concrete to get the cascades out of the mold surface? I also think if you add some portland cement to the mix I feel it should have come out better
@@RedandAprilOff-Grid I watched your video to strengthen concrete you need to add fiberglass chop strands none of the wire you used was strong enough you need to add 3 pieces of number 3# rebar or 2 pieces of number 4# rebar the wire you used did not have any linear strength I am not sure of the formula but you need to add ready mix with your aircrete or add rocks and sand to it to add strength I will see if a friend of mind has a formula for mixing but you need to add fiberglass or rebar to make you casing strong I feel you need to get the right mix and add rebar your footing pour don't have any strength and you could take a mall and crack without much effort
How did you guys learn this? Did you take a workshop. Did you try different soap? Did you make a homemade foamer. I found it verys alot if your foaming machine is tweaked one way or the other.
No, we didn't try it. Someone mentioned that if fibers are not fully encased in the material, they are not very effective. Which makes sense. It was getting too cold to continue testing, and that's also likely why out later batches were turning out so poorly. Aircrete seems to be pretty temperature sensitive, which also makes it a difficult material to build with.
I applaud you all for taking on building your own home. Seems to me you took on a course in materials science and engineering, without having an instructor to help you know the chemistry and physics principles in play to explain what you experienced and figure out how to make changes to get what you want. I agree with commenters who made a point about the environmental changes (due to weather) that impacted your results with the aircrete blocks. There are chemistry and physics principles at play that commercial operations tightly control so they get consistency in production variables. Your experiments show how sensitive materials can be to the environment. I wish you well with your new approach and hope the result is all you want it to be!
Thanks! We also learned that aircrete isn't an inexpensive material to build with. The house we built was easier, and less expensive. It's also heated completely passively in the winter from the sun. We are very glad we didn't use aircrete. 🌞🏡 🏜️
I've often wondered why one can not use a drier foam. So higher air pressure. Then you mix the cement slurry, and then start mixing in the foam by fixed water volume. Then keep mixing until the volume reduces to the calculated volume. I am sure that longer mixing will pull the extra air out. Then one will end with a given amount of cement and water and aim for a target volume instead of hunting the foam density. Can this not work? I also think that adding a cup of Bentonite clay in stead of Glycerine, will get the mix smoother and help to trap smaller bubbles. Bentonite is a ultra fine clay that chemically reacts with the cement on curing. So the product should be harder. Cat litter is often Bentonite. Not always.
@@RedandAprilOff-Grid It is worth a try. As long as it is not freezing, temp is no issue with cement curing. It may affect the foam density though.. I am planning on building a Gothic Artch house here in Sweden next year. So Aircrete. I want to pour directly rather than make and use bricks. Also a good and easy coating is cement and salt, 50 50 and water to the desired viscosity. hardens the outer surface and can be used with fabric. I apply it with a soft broom.
@@heikkiparviainen6084 That sounds awesome! Best wishes on your build! Aircrete is tricky stuff, but I'm sure it's possible to get it right. We still need to finish the plaster on the garden wall, we might give that recipe a try. Maybe the salt would keep it from freezing. We tried to keep it protected, but the plaster on the first section has white patches where it froze.
I appreciate Tiny Giant Lifestyle YT channel on aircrete, as he demonstrates that micro-cracks are a non-issue if you apply reinforcing mesh on both sides, and this also eliminates the strength concerns. If you have a rigid frame and are using aircrete to fill in the blanks, how much stronger than rigid foam does it really need to be?
We were planning to add mesh and reinforcements, but decided we still didn't trust it to last 50+ years. Even autoclave only has a 30 year lifespan, which isn't great. Once it starts crumbling it turns to powder and it can't be repaired. We decided there are, better, cheaper and easier materials to work with.
@@RedandAprilOff-Grid you can buy the Styrofoam pellets by the bag. I think you can also buy the blocks. The blocks interlock, and you stack them dry, then you push the rebar through the holes, then fill with slump.
It was in the fall and just starting to get close to freezing. Yes, we suspect the water and Drexel were too cold, and the curing temperatures weren't ideal either. Most of the year is dry here.
It wasn't great. Someone mentioned in the comments, that the fibers need to be encased in a solid material for them to have much benefit. With the holes and overall weaknesses of the aircrete we tried them in, the fibers didn't seem to help much. In a lower foam mix with smaller bubbles, there would likely be some benefit.
When we made our first batches, we were in the low 80s in the day and getting down into the mid 30s at night. We kept the samples wet and covered in plastic for 7 days. The last batches we had to let cure in our well house to keep them from freezing. I suspect the cold Drexel was our main problem with later batches. It wouldn't have been practical in our situation, but using warm water may have helped.
It had occasion to talk with the folks that have been making it commercially for 50 years in Europe when they tried to move into U.S.markets. There were two key things that they did. #1was that they mixed aluminum powder that slowly gave off tiny bubbles as it reacted, so it poured into molds without bubbles and then rose like baking a cake. Then once it roseto the desired amount the mold was heated to speed and finish the chemistry that gives concrete its strength. I still have the sample in I use as a trivia on the stove. It never gets hard against abrasion like regular concrete ( being able to cut it with a handsaw is considered a feature) an will always need protection from abrasion, but it does not fall apart like your sample. As I suspect that the change in quality might have been due to temperature as much as anything else (and the original invention was in Sweden) that would be a good reason to run steam along the outside of the mold.
😎 Yes, this is more of a DIY method. It makes aircrete but a lot can go wrong and the results can be inconsistent. I suspect the the colder temperatures were affecting the foam, and using warm water in the soap solution may have helped. 🌞
@@RedandAprilOff-Grid the fine aluminum powder used for fake guilding is readily available, and the water/concrete mix makes a big difference in strength, but keeping the result as close to 180 f is the critical difference I think. I did not think so at that time but by doing that they got consistently even more than specific strength. Metal molds would not be that hard and a way to have the steam run underneath even at normal pressures and even just doing that alone would give better results than the best you got, and the difference affect you as long as you lived there. Using just warm water or even hot water would cool too fast, The chemical reaction can take several days in the best of circumstances which is why they wait si long to build the next floor.
All samples were watered twice daily and kept covered and wet for 8 days before testing. We were not able to control the temperature, and it was likely a factor when making the last few batches of aircrete.
We didn't quite get it figured out. It's tricky stuff, and overall a big pain to make. Our best guess is that the colder temperatures were causing our later batches to fail. Thanks for watching! 🙂
We were planning to add wire mesh or some other kind of metal support, and also fiberglass fabric and plaster on the inside and outside. Our testing was to compare the different aircrete batches against each other, and see if we could make consistent batches. I tend to think now, that the wire support would eventually make the cracking worse. Our garden wall shows significant shrinkage and cracking.
They were wet cured for 7 days, and then tested wet. We figured with a standing wall it wasn't going to be possible to keep it wet for a full 3 weeks, and the tests were to compare the different recipes and our ability to make them. You are welcome, hope you can learn something useful from it. Here is our aircrete videos playlist ruclips.net/p/PLW_v9VWGwCM_gdAXzuKTr8J13rTZ1DSpx
Just a bit late to add a comment question.. But just wondering if you had similar experience i had in Western Australia.. My first samples were stable and strong.. Some failed miserably when i tried getting more volume by increased foam and less portland cement.. But I had total failure of the next lot and couldn't for the life of me work out why.. Some investing i find not all Portland Cement is equall on the market and this particular one had refractory ash added in very low % but seemed to be the killer...
There was a shortage at the time we were doing this, so we ended up using various brands of portland cement. It was hard to tell, if there was much difference between them. We decided there were too many variables, temperature was also an issue. Our winters are cold, and we didn't want to wait until spring. 🌞🏜️
I worked for a roof and roof deck company back in the 90's. We used "light gage metal cee's" to make trusses for schools, Structural Engineer designed and all that. However, these weren't the 24 or 26 gage cees used for interior, non load bearing walls. These were up to 10 gage, mostly 12-16 gage.
We covered them well with plastic and wet them down 2× a day. We knew on our house we weren't going to be able to keep the aircrete wet for more than a week without lots of forms and big expense.
@@RedandAprilOff-Grid Totally understand the limitations of resources for this kind of thing is a spammer in the works. Just the inconsistencies of the many tests must really frustrate you. Hope you are getting better results with new materials. Inspiring. 👍👍
I've done some testing myself and your foam concrete looks like is doesn't use enough sand. What I've done to make it more durable and reduce big air bubbles was to increase the tenside amount and foam it to 30g a litre. I also increased the amount of sand but used very small construction sand. I also added hemp fibres to it. The resulting bricks behave like hard plastic. The denser foam can hold the smaller sand much better and hemp fibres gave extra support. If you need tensile strength you need to add a large mesh structure of some kind, small shredded fibres dont help much and can even make it more brittle. You need long intertwined organic fibres or a glassfibre/metal mesh or similar. If you want to cheap out and have an easier build I'd use earthbags instead of foamconcrete. Foamconcrete is hard to make and needs exp. or one needs to follow a recipe exactly for it to be good.
Glad you found something that worked. Aircrete is tricky stuff. Some of our earlier batches turned out really well. We have videos showing the methods we used, and different things we added and tried. We suspect the colder temperatures were the main issue with our later batches, but there were probably other contributing factors. Regular aircrete doesn't have sand, but we tried some batches with finely sifted sand, it almost worked. It had awesome compressive strength, but the batch fell slightly, and sifting the sand was a lot of work, and it was heavy and hard to mix. Best wishes on your aircrete projects! 😎
Did you test the alkalanity/acidity of your water? I feel your issue is related to something in your locality if you’re assured you followed the mixing instructions as given. I trust a perspective shift might benifit your process outcome. Cheers!
We used our well water and a portable water softener. Once we got the hang of it, our first batches turned out great. We figure the colder temperatures were to blame for the batches getting worse. Maybe it's possible to get good consistent batches if you are working indoors, it have a nice long spell of ideal temperatures. We are glad we moved on from aircrete, and we should be done with our house in a few weeks. 🙂🏜️
When the batch turns out right it fills the form in nicely. The main reason for air pockets is overmixing, a leak, or an unsuccessful batch where too many air bubbles pop, and you end up with voids.
As a residential designer that specifies the materials on house and addition projects I hear from customers interested in all sorts of building systems. A lot of folks lock onto a particular system as the answer for their dream home and I always need to ask what the question is that material answers. It's really easy for people to get caught up on the miracle system that does it all but the choice needs to be based on the sum of a bunch of questions. What is the local climate and what are the site risks, what is the ability of the client to pay, what kind of materials are locally available and meet the clients desires and finances, what are the local trades capable of doing with proven competence are a few of the issues, and there are a bunch of other questions that need to be answered. I have never gotten to build in the desert but if somebody offered me a project on a big lot in an arid place I'd start by looking at what the locals have been doing for the last thousand or so years. If you want low carbon and low embodied energy you're going to minimize concrete, styrofoam and steel. If longevity, healthfulness and sustainability are important then start thinking adobe or rammed earth at a site like this. Wood is good.
Aircrete sounded interesting, and people were saying it was less expensive and had a lot of insulation value. It turned out that neither were true. We are so glad we went with something different. Out house is performing amazingly well and is heated completely from the sun, and with our cool nights a simple evaporative cooler works great in the summer. Our son is currently building a hyperadobe house. It's pretty cool. We are currently sharing his build on our channel. 🌞🏜️
Temperature's surely could be a factor. Maybe in a stable environment, same temps, etc the results would be the same. Thanks for sharing the information.
That is quite possible, the Drexel foaming agent says on the label that it need to be used at room temperature, and our RV was getting pretty cold at night. We tried setting it out in the sun in the morning, but it was still pretty cold, and our well water was real cold too.
He used Chief Architect, they have a monthly subscription option. Red has a Bachelor's degree in Business Administration. Woodworking and building have been a hobby of his for a long time.
My first suspect from what you are saying and your inability at replication or improvement through ingredients would be hydration, mainly because you did not mention it yet it is one of the most important factors in strengthening concrete. How did you hydrate this during curing and for how long did you cure it ? Did you keep it covered during hydration / curing ? Did you use any plasticizers or water reducers or additives like fly ash, slag or silica fume ?
It was all explained in previous videos. The samples were all treated the same, covered in plastic, and watered morning and night for 7 days. Then we tested them on the 8th day to compare the different batches and recipes.
We looked for somewhere to buy fly ash, but we couldn't find anyone that would sell it to us. The recipe we used, is in the description of all of our aircrete videos.
Hi Red & April. I followed along of most of your aircrete vids. Others too here.. ive never liked the folding in of the cement into the foam. What if your paddle mixer was 4 very fine sieves and the dry cement was mixed into the foam. The tiny holes in the sieves would continually aerate the mix as long as you need. Great series of vids. Thanks.
From what I understand, cement needs to be fully saturated with water to set up properly. When mixing in the foam, if dry cement is still stuck on the sides of the barrel it causes problems. But you never know, it might work. Thanks for watching! 😊
I am no architect but I have worked construction for quite a few years on your c Channel trusses you should be fine just using them as is look up how much load it can actually Handle by the thickness of it and how long it is another thing to think about is you should put wood purlins on it so you can attach the metal sheeting you also want to put a vapor barrier between the metal in the wood to keep down wrought and good way to attach the wood to your c channel is a Ramset make sure you get the right 27 caliber charge but this will be quicker than using screws because you literally just push it up against the wood and pull the trigger screws will burn out and drill bits will burn up it's a very cost-effective way to attach wood to metal but make sure you only use this against heavy metal not the sheathing it will just blow a hole through the sheathing
If I were making a tiny retirement house in the high desert, I'd just go with cinder block. For coolness, I'd make an extra-high ceiling and tile floor. Can always cover it with a rug in the winter. Two stories might be best: appliances and summer sleeping downstairs, winter bedroom upstairs. But then as you get older, you won't want stairs. Anyway best of luck.
Because of the extreme temperatures we get here, we wanted to build a house with good insulation. We ended up going with 2×4 framing but we added exterior insulation. Along with the passive design and thermal mass our house is heated entirely from the sun in the winter. The stable even temperatures are amazing! Thanks! 🌞🏜️
We have urban/ wild land interface fire codes here so any new construction or window replacement needs to comply. At least one tempered glass pane in an insulated glass panel. Easy to order from major window and door manufacturers. Siding can be stucco, cement board or metal. Try to skip the rigid foam since it is extremely flammable. Rock wool is expensive but fireproof.
We used metal siding, so there's not much risk of fire. The complete envelope around the entire house as well as the reflective properties of the foam board have worked out amazingly well. We also added a lot of thermal mass on the inside, so our house maintains its temperature really well.
A "failed" experiment is the one not attempted. Thank you for your work.
Fibreglass coating inside and out
To me it seems the biggest macro factor in your experiments that parallels the decreasing results in quality is the fact that the seasons have changed from warm to cold. Maybe aircrete is just a lot more fickle when it gets cold.
And others have pointed out that aircrete by itself is not meant to have a durable surface, nor deal with tensile forces. So for others who are considering aircrete, you'll want to evaluate how it fits into an overall system, and not just how it performs by itself in impact and tensile strength tests.
And also re: direct contact with support beam- Any time two different materials come into contact with each other it's good to plan for how they will move differently, and the problems that could cause. With weight bearing aircrete you would probably want to pour a concrete bond beam, or if used for insulation, using a material with some flexibility or elasticity between the aircrete and the solid material.
Yes, the colder temperatures were likely a factor. Drexel says on the label that it should be kept at room temperature. We tried to warm it up some, but I'm pretty sure it was still colder than would have been ideal.
These were comparative tests, intended to test the mixtures against each other, also to see if we could get consistent results, and make an aircrete that wasn't overly powdery or brittle.
This was a hella helpful comment. Thanks
@@RedandAprilOff-Grid I believe that when using the Drexel foaming agent, it needs stay in the consistent temperature range throughout the curing of your aircrete over several days. The foam will degrade when it is not at optimal temperatures. This will degrade the structural integrity of the aircrete as it cures.
Also, the quality of your water is a determining factor. If your water changes in hardness it will affect the longevity of your foam. A shorter foam longevity means that it will collapse before the aircrete has cured. I understand that soft water makes the bubbles last longer. You could try using some water softener salts to see if this makes your foam stronger.
But keep in mind that aircrete is never going to be as strong as concrete. Simply put, air is definitely softer than sand. You are replacing sand with air trapped by a foaming agent. Aircrete is more of a replacement for fiberglass insulation. It is not a structural replacement for concrete in a stem wall, or foundation.
If used correctly it can add rigidity to a structure and better air sealing compared to fiberglass batting between free-standing / rigid structural members of the building.
From everything I have seen it is certainly more of a wall material than a foundation one. Also the comercial Aircrete blocks are all rather large. They are thicker than cinder blocks, longer and taller. That may have just been that companies being lazy, but I think it does need to be quite a bit more substantial to make up for it's weakness.
@@SoralTheSol many so called Aircrete commercial products are cooked to cure them in steam autoclaves, and loaded with styro foam!
You guys made a really good effort and your evidence based approach has been invaluable! Thanks again for sharing the process. I think your decision makes perfect sense.
Yes, we really wanted to make it work, but we just have to cut our losses and move on. The time testing aircrete has been interesting, and while we have been making and testing aircrete the cost of lumber has finally come back down. Red likes working with wood much better than aircrete anyway. OSB was $58 a few months ago, and now it's $21! 😊🏠
@@RedandAprilOff-Grid never give up! Success will be obtained for every effort!
@@RedandAprilOff-Grid I have an idea what your issue might have been and two solutions. Besides weighing the foam to check it is the right density, the glycerin separates out and floats on the top of your foaming agent (drexel). This leads to early batches being good and later ones with low to no glycerin where bubbles are weak. The other thing that can make aircrete more stable and more economical and insulative is to add polystyrene filler instead or as well as foam.
@@jonathanberry9502 We added 1 Tablespoon of glycerin to each batch and used a new well mixed bottle of Drexel for our last few batches. My best guess is the cold Drexel was to blame. We tried to keep it warm in our RV, but our RV was still pretty cold. Later we learned that adding warm water to the Drexel may have helped, so that's what we would have tried next.
@@RedandAprilOff-Grid Thanks, I am currently considering an polystyrene version aircrete to make a floating island/houseboat.
Batch to batch consistency with aircrete is really hard. Recycled, granulated styrofoam is a great stabilizer. It's free. It keeps EPS out of the landfills, it's bug-proof, and it makes batching your aircrete much easier. You still will have to coat the molded panels with a glass fiber matt. Stucco is a great option for aircrete.
I would have thought that you would stucco over any exposed aircrete to prevent exposure of the elements anyway. Personally I would hard render (stucco) both inside and out. Also I would plaster the inside on top of the stucco for a nicer finish. I have never used or made aircrete. In South Australia they call it hebel, and a factory makes it.
Did you ever consider Bio Styrene.
Sort of like home made RASTRA BLOCKS !
I understood that styro doesn't bond with cement. Also it decreased the heatability because it melts at low temp.
@@nebulousvoid I've built buildings with RASTRA BLOK; which is a Styro and Cement CFS, with 6 inch cores filled with concrete and was pleased with the results. ps. direct flame would not melt the Styro due to it being encased in cement.
“I never lose. I either win or learn.”
Nelson Mandela
But... learning by mistake is a long and expensive process.
Thank you for sharing your experience, good or bad. It sure help other to go faster.
Thank you for sharing failed experiments along with the early successes. So many videos are just exciting preliminary results with little follow up.
Thanks! Yes it was hard to find good info about making aircrete, or it's long term durability. I watched everything I could find, and messaged a lot of people, but we still had a lot of unanswered questions. Hopefully people can learn from the good and the bad of what we tried. 🌞🏜️
I wouldn't give up on aircrete yet! Regarding the testing of your aircrete block under weights, I feel this is a flaw in understanding the strength of aircrete as the blocks were lacking any reinforcement fabric. You need to use a reinforcement fabric over the surface of aircrete which is what attributes to the strength of the aircrete, as well as the shape of the dome itself, if making a dome structure. The blocks by themselves would undoubtedly crumble due to the porous nature of the material. One simple comparison I can make for this might be to consider a foam poster board. The foam by itself on the back of the board will obviously scratch and puncture easily. With the reinforcement of the poster board with the foam, the entire unit then becomes incredibly strong. That is sort of like how aircrete would work as a structure. You absolutely need the reinforcing fabric to give it its strength.
Yes, aircrete definitely needs to be covered in fabric and plaster. Our testing was to determine if we could make good and consistent aircrete batches, and to compare different recipes. We decided aircrete was not going to be a good fit for our house design. We are continuing to see shrinkage and cracking in the garden wall. Using fully cured blocks would be the only way I would build anything out of aircrete.
Another issue is that concrete is not strong in tension. When you test your blocks by supporting the ends and putting weight in the middle you put the lower side in tension as the block bows. Any concrete will fail like that. Why is this test relevant to your building? Is it so that you can use it as the head of a doorway? Note how the Romans did that as an arch so that every component was in compression.
My experience is that Aircrete is just not great for loadbearing. Good in supplement to more reinforced material, good to work with, but it lacks the strength of other forms. I've only had success when making it in blocks, rather than poured forms but that is probably a matter of operator skill rather than an inherent limitation
@@CnhaddockCan graphene help with this?
Its tough to start from scratch, I admire you guys and your efforts. Keep up the good work.
Thanks! 🙂🏠
Your experiments are a success of what materials not to use in certain circumstances. Thank you so much for you time and effort. One year later and I hope your home is strong and secure with all you need it to be.
Thanks! Yes, just putting it out there for others to learn what they can from it. It was an experience, and made us really appreciate conventional building materials.
Our house turned out amazing, thanks!
Good choice. All the test batches and effort was worth it. You learned valuable information. Thanks for sharing
It was definitely an experience, glad we were able to share it, and hopefully others can learn something from it. 😊
Yes! Now you are on the right path. No more need to be running test samples for weeks and weeks and getting frustrated. Now you can build and be confident of strength, quality, and durability. Aircrete was very frustrating for me also. I just could not figure out why I could not get repeatable quality aircrete. Cracking and powdering are all issues I encountered. And do you think you can just repair aircrete?...not with the powdering. So glad to see you are moving along with other tried and true methods.
Thanks! Yes, we are so glad to be moving on. We really wanted to make it work and liked it's properties and the idea of doing something different, but it just wasn't working out. The thought of having the inside of the walls eventually turn to powder, was looking like a real possibility. If we could have made batches like the first ones every time, we would have went ahead with it.
I'm pretty sure the cold temperatures were not helping anything, but I also wonder about the Drexel. As other channels have mentioned, it seems like the first batches with a new jug turn out awesome, and the last batches turn out terrible. So, when we opened a new jug and mixed it well it just mixes the good and bad parts of the Drexel together. Then we had batches that didn't fall, but also weren't great quality, because they had the grainy stuff mixed in from the bottom of the jug. 🤷 Just one more idea of something else that might have contributed.
How is the dome going Jon? No updates on your channel for awhile!
@@zacwhiting1563 Hello Zac, It is on a long-term hold. Like so many other people, Covid-19 and job(employment) problems have kept us from our home on the island. We are hopeful that things will get back to normal soon. In the meantime, I am tinkering with a Tri-Magnum build. I may put some videos out on this.
@@RedandAprilOff-Grid May I ask you, if you ever tried with dish-soap as many suggest, April??
@@paulwyleciol3459 No we just used Drexel. Suave Clarifying Shampoo looks like it might be a good option, but you need to use a lot of it so Drexel ends up being less expensive. Maybe some of the other types of soaps do better with cold temperatures. It's worth a try.
I just wish you guys all success. I know what it's like to have to make radical course changes during a project. It always hurts. But, life itself is really a grand collection of lessons learned.
Thanks! Our house turned out great! We are SO glad we didn't use aircrete!
one way to make it more consistent with its strength and also to improve thermal resistance is adding styrofoam to your aircrete mixture, a lot more thermal resistance and the strength of it is still very good, the only issue is it'll flake against the elements. you need to wrap it with fibermesh then stucco it or like Stephen Williams stucco+limestone. you can find a bunch of neat videos from Stephen Williams on how he built his work shed with it as well as an arched gardenshed now.
Styrocrete looks like quite the process. We personally weren't interested in driving all over town trying to find styrofoam. We don't live by a large town, & we would need a whole lot to build a house.
I know it's all the rage right now, so we should be seeing styrocrete structures popping up everywhere soon. It will be interesting to see how it works out for people. 🙂🏡
Congrats. You all weren't completely deceived by crap on social media. Social media is all about getting viewers...not valid info. It's full of many things that makes people wonder "why aren't all homes built this way". There's always a reason.
It sure is hard to find good information about it. Aircrete is interesting stuff, but I definitely wouldn't want to build a house out of it.
Let me start by saying, thank you for the awesome video! We need more of us!!
However, I'm not sure I agree with your statement that you've "controlled the condition." You never developed a real consistent process. You changed the formula half a dozen times over no more than two dozen batches. You did not measure temperature of the material or ambient temperature for your cure. and as you mentioned you don't seem to have used the same mixing times. Cement is very sensitive to ambient moister and temperature as it cures; mixing time (adding heat into the cement) can also effect cure times. Add to that the fact that the foam is going to loose structure the longer the cement stays open, means you're definitely going to have inconsistency no matter how well you control.
I've made about three batches using the same Domegaia set (the newer Dragon XL version). The discrepancy (I believe as I've observed) is due to the fact that the author of the material built these domes in climates which stay stable, well within the cure range of Portland cement. Your place looks like our. COLD! Which means we're going to have huge fluctuations in temp thought the cure process, making it seem like we're not locking in some other factor. IE Did you start every batch at the same time of day, and where they exposed to the same ambient conditions.
A really good control (which I need to do if I'm going to cure in the dead of winter) is to enclose the forms in a temperature controlled enclosure, that could keep a nice consistent 60F (the optimal cure temp for Portland cement).
The ASTM compression test, uses a hydraulic press with a pressure gauge to test for compressive loads on cylindrical core sample size. The method you used is excellent when considering whether to use this for a lintel or to span an area (which aircrete is not for), it does not inform much as to how much actual compressive strength is available in the final monolithic structure.
Adobe only provides about +300 PSI. CEB provides well over 3000PSI. aircrete falls closer to adobe, but still has more than enough strength (even your worst batch, maybe not the cellulose added one) to build a 10 foot wall that is 12 inches deep (no load).
Compressive strength is very different than tensile strength. Though aircrete is brittle, and does not have the same tensile or compressive strengths of concrete, it has a very high compressive to weight ratio, which makes it ideal for small structures such as domes and arches where the nature of the structure itself provides load mitigation, and where you're not exceeding the load limits.
You can build very strong arches (especially Catenary arch) and domes with the stuff.
Most of the materials (even what you would consider failures) can be used in a dome with re-enforcing fabric, and once you have the scratch coat and the finish on it, despite the lack of tensile strength (increased by the wrapping fabric), you now have a strong monolithic structure. Resistant to wind and weather, with far better insulation factors than any conventional frame house you could build, and in the process building an environmentally friendly and cost effective home.
I can certainly understand the time constraint, that is a different story. I'm sleeping in a tent, in the dead of winter, build on our property; and as crazy as I am in loving every minute of it, I certainly can't expect my better half to be able to withstand it. So I think your conclusions on aircrete are possibly driven by other factors and not aircrete itself.
The inconsistency is not in the product, it is the way in which we (you and I) are producing it, all of my problems with it so far, have been basically self induced.
Yes, based on other aircrete channels we were watching, we knew it was going to be difficult to get a consistent product, but it was even more challenging than we expected. We started at about the same time of day for all of our batches. With the first samples were made in the afternoon, we were in the low 80s and ended up pretty close to freezing every night. We were expecting to be able to make aircrete through most of the winter, but our particular location is often 20° degrees colder than the surrounding towns. So that was a huge bummer. Yes, I think the cold Drexel was likely our main issue after the first batches. Also, if the first part of the jug makes awesome aircrete, and the second half of the jug doesn't work at all, what does that say about Drexel? Harry showed it keeps it's volume way more than other foaming solutions, but what he didn't show, was the large amount of water in the bottom. We are living in an RV and doing everything on solar, so there wasn't any great way to keep the Drexel at room temperature, or to heat the water. That may have been the issue, but the problem of cold wouldn't have gone away until well into spring, and in the spring we get consistent dry winds, which would have made curing an upright wall extremely difficult. If we could have got successful batches in the fall, we would have been encouraged to continue, but if it's that temperature sensitive, we we decided it just wasn't going to work for us. Best wishes, I do think it can be done, we just don't want to spend years trying to get it to work, and we don't know enough about the long term durability of the aircrete. We could imagine it eventually turning into powder inside the walls. It will be interesting to see how the garden wall looks in a few more years. The tests we did were to compare the different samples to each other in a fairly consistent way.
@@RedandAprilOff-Grid Thank for the awesome insight. I look forward to watching your continuing adventures 🙏🏻😇
Was it by any chance cooler and more humid with those successful tests? I learned if any concrete dries too fast, it cracks and crumbles...or was the heat and humidity the same during pours? I know you've moved on, but would love to know if it's worth it to invest in a hopper that measures those variables in it's mixture ratios so the batches all come out the same. Super important when needing to make a consistent mortar, too, so the walls don't crumble later if they cure at different rates and contract/collapse. Thanks so much for sharing your efforts!
We figured as long as the temperatures were staying above freezing it would be okay. I think by the end, it was getting too cold. The well water was cold, and the Drexel was too cold. Now people seem to be saying if you add warm water to the soap solution, that should fix the problem. Which would not have been practical for us since we are off the grid and running everything on solar. We didn't realize temperature was such an issue, our 100°+ summers probably would have caused issues too. Measuring the materials wasn't difficult, but mixing them together really well was. We were planning to buy a mortar mixer, and sell it after we got done. There are so many reasons we are glad we didn't build with aircrete. Leaking forms, shrinkage, cracking, labor, cost, cure time. We found the whole thing to be a big pain. It's also unknown how long an aircrete structure will last, and I think there are better building material options out there. Aircrete is an interesting material though, and I'm sure it can be done. Best wishes! 🌞
Sorry to hear the original plan wasn't working. Thanks for sharing your experience though. That is really good info to know.
Looking forward to seeing the rest of the build.
Thanks! It was a learning experience for sure, and we are excited to get back to work building the house. Our first delivery of materials is set to come on Wednesday. 😊🏠
This was extremely helpful! Thanks for sharing. Glad RUclips recommended. I won’t bother sourcing the materials. THANK YOU!
Glad it was helpful! We are SO glad we didn't try to build our house with aircrete!
@@RedandAprilOff-Grid Testing batches was very smart! Most people would slop it together and worry later. I’m glad time and common sense was on your side.
Thank you for sharing. Comerciallly, aircrete is cured in a controlled environment and the bubbles are produced by a chemical reaction that can be controlled by recipe. This is the difference between CLC (what you have made) and AAC (commercially made). AAC is cured in a temperature controlled pressurized oven. I’m sure your results can be attributed to the cement moisture exposure prior to curing or temperature/pressure changes with weather. That’s my guess anyway.
Thanks for watching! There is a lot that can go wrong with homemade foam aircrete. The colder temperatures were probably a contributing factor too. Glad the prices on materials went down, and we were able to build our house through the winter. Glad we didn't wait until spring.
@@RedandAprilOff-Grid if you had made it above 65 degrees, might have worked. All epoxies, glues and quikcrete state above 50 or 55.
@@WubiWatkins The temperatures were in the low 80s when we were making the first batches, and mid to low 70s for the later one's. It was getting down below freezing at night for our last batches, so we had to keep the last set of samples in the well house to keep them from freezing. The foaming agent Drexel also needs to be kept at room temperature, and it was likely too cold. Adding warm water to the soap solution might have helped.
@@RedandAprilOff-Grid could have been a supply issue? Just trying to help. Hate to see you give up your project that you were trying to do
How long have you had that cement powder? It has a shelf life. After three or so months it is starting to absorb enough moisture from the environment to significantly affect its strength. Obviously that number is affected by how well it is stored and the humidity in the area, but as a rule of thumb...
It was purchased within a few weeks of using it. There was a shortage in the stores when we were trying to make these samples, so we tried a few different types.
Adding fiberglass might help with strength and structure...
I did notice that you had a bunch of bags of quickrete... that may affect your batch consistency once you bring the bags home and let them sit outside they can lose quality fast
Thanks for that useful vid. That will help a lot of people. Not everyone would show a failure.
I applaud the time and effort you put into your Air-Crete investigation. Glad to see you are moving on. Lessons learned in a controlled environment as opposed to potential consequences down the road.
Thanks! Aircrete is interesting stuff, and I'm glad we were able to share our experiences. People may decide it's not for them, or they may see ways to make it better. A plus for us is that while we were making aircrete, the price of lumber went down. We are excited to start building our house! 😊🏠
You mentioned being able to build the way you choose. If you don't mind me asking, what state is that in?
@@LucidDreamer54321 We are in Cochise County, AZ.
You were so methodical in your aircrete attempt I thought if anybody could do it you would. The alternative to aircrete that I thought was most promising was using ground up expanded polystyrene packing instead of foam. It comes out very fireproof, fairly strong and good insulation. The biggest advantage is consistency without having to rely on foam. There is a company in Phoenix that makes blocks of this material which stack together like Legos and then concrete is poured through the openings to lock them all together. The walls still have good insulation. Another guy on RUclips built a garage using ground-up polystyrene and cement mixture for the walls and he even tamped them from the top as he was pouring . He then built a second story on the garage to prove the walls were strong. Supposedly you can get the polystyrene packing from furniture stores etc and save it from ending up in the landfill. But you still have to go to the trouble to grind it up.
Yes! Agreed! Also when 3m was forced to change the formula on styrofoam it's only the glue that is flamable. Once it's shredded, it won't burn. Silicone foam is flame-retardant, self-extinguishing & can withstand 2100 degrees F flame for more than 10 minutes without burning. I was shocked when I tried it myself. Also the silicone foam and AirCrete mixture is what's currently being used in Asia for home building , yes, even on load bearing walls.
@@bhing1483 Could you be more specific? Silicone foam? Styrofoam (XPS)?Expanded polystyrene beads (EPS)? packaging
just to be clear the guy who made the garage was using AIRcrete with styrofoam which is differtnet than EPSCrete which is just normal cement and styrafoam. ruclips.net/video/6U4JAop0dTY/видео.html
@@khandam7709 I just watched the video again and you are right, he mixed aircrete with what he called styrofoam. What he calls styrofoam is actually expanded polystyrene beads (the most common packaging material, commonly ending up in landfills because it can't be recycled easily like a lot of plastics). Since he tamps this mixture in the walls he can't be thinking that the bubbles of the foam are being retained, can he? He claims the aircrete is just acting as glue for his styrofoam. Why would mixing foam with the cement make it any better glue? @4:18 ruclips.net/video/27v7Oq-q9xs/видео.html&ab_channel=StephenWilliams
@@firstdayof1 xtruded styrene foam blue or green sheet goods. Expanded styro, white beads.
As someone whose only experience with air crete is “I watched a few videos,” I would just add that some claim to get better results with foam crete, using a soap-based foaming agent to “fluff” the mix. I should add these videos were made by people who were promoting/selling the idea of foam Crete, so of course they may not be the most unbiased source, but a suggestion if still considering. I applaud you for trying this build, and doing so very reasonably and methodically.
Thanks! Yes, this is soap based aircrete, with Drexel as the foaming agent. My best guess is that the Drexel was getting too cold, & our night time temperatures were starting to get below freezing. We kept the samples wet and protected from freezing but it still wasn't ideal for the curing process. Aircrete is tricky stuff. I assume the hot summer temperatures wouldn't have worked well either.
Thank you so much! The videos and experiments you made will be of great service and value to many others, so please don't feel your work has been a waste.
And if i might ask- many of us would be interested to see an update on the garden wall in the spring or in a year.
(And if you have space to keep the samples, maybe evaluate them once they've all had a chance to fully cure and age a bit. I have a feeling a few of them might behave differently after several months)
It was an interesting experience, and I'm glad we were able to make videos that others can learn from, even if it's just so they can see what we are doing wrong and figure out how to make it better.
We are mostly just relieved we won't have to deal with some of the challenges and uncertainties of trying to make aircrete work, and we are excited to start building our house. Red likes working with wood better anyway, and the prices have finally gone down. 😊🏠
Yes, we plan to show the upcoming progress on the garden wall. We also plan to build an outdoor rocket mass type stove, and maybe a pizza oven with some of the larger aircrete sample pieces.
Did you try using Perlite instead of foam? It makes perlitecrete, much more consistent properties.
No, we figured it would cost a lot more, and we would need a large storage storage space and whole lot of it to build a house.
A bit of summary for my own brain. 😆 (some of my own thoughts included)
- while air Crete is a cool material, and someone else might be able to build a house with it, it wasn’t a good fit in this situation for full-wall construction due to batch consistency, compressive weakness, powdering, and microcracks.
- difficulty with overall mix consistency despite increased efforts to control for all possible variables. Inconsistency carries the risk of having some good spots and some bad spots in the same structure and even the same wall.
- bubble size, issues with large bubbles despite trying additives and nailing down density/quantity. Same risk as with overall consistency.
- micro cracks on the surface even in fiber reinforces mixes indicates a risk of long term surface weakness/ potential spalling. Even with surface bonding cement, if the outer layer is weak it can spall. This risk might be ok for a shed but not for a long term residence.
- it’s tendency to powder/give way with light pressure is incompatible with the need for lateral support of the metal posts against twisting and bowing.
- erratic/low tensile strength carries the risk of exterior wall panel failure in the case of high wind gusts and other weather impacts.
My own take away, is that aircrete is a decent insulator, resists pests and especially wood eating insects, but is not structural and should be treated like an insulative material (like rigid foam or rock wool) This matches what I have concluded from aircrete experiments by others. If this conclusion turns out to be accurate, then increasing the insulative capacity instead of the strength capacity makes a lot of sense.
Yes! This is a great summation of our results and conclusions! 👍😊
The lighter mixes are just so weak and crumbly. I'm not sure how well they would hold up even inside a wall, especially if the wall gets any kind of vibration or impact. The stronger mixes are much less prone to crumble or turn to powder. Our strongest mixes probably would crack, but I don't think they would turn to powder like the lighter samples that had bigger air pockets.
How many days did you let these test blocks cure before you tested them? Concrete gets stronger after 20-30 days
We let the samples wet cure for 7 days. We knew there wasn't any way we could keep our house walls wet for 30 days, and it was a comparative test between the different mixes. We also tested the samples dry a month or so later.
Aircrete is meant to be built with self reinforcing geometries like domes and arches, just like Roman concrete, then encapsulated on both sides with fiberglass or basalt mesh. When it is kept under compression and encapsulated with these tensile layers it is strong enough to even be earth buried. Straight walls are not recommended.
Good luck with your build.
I'm sure Roman concrete was much stronger than this stuff. Aircrete is a whole different thing and has way less tensile and compressive strength than any type of concrete. Plaster would help, but with pressure, our samples compress down and turn into powder.
Thanks! We are excited to get this house built. 🙂🏠
@@RedandAprilOff-Grid Indeed. It is 70% air after all. It was never meant to pass the tests that this channel put it through. Neither would styrofoam, another product that is mostly air. The benefit of Aircrete is that it can be created from scratch, formed easily, manipulated very easily, insulates well, is fire proof, rot proof, bug proof, and water retardant.
Making long blocks then placing weights in the middle to test its tensile strength is the opposite of what it is good at. Pressing direct pressure over a small, localized space to test for compression, is not what it is good at. Aircrete is a lattice of cement bonded around air bubble geometries.
It distributes loads well.
When Aircrete is spanned across a distance, stacked in an arch or otherwise round shape, encapsulated in an exoskeleton of tensile reinforcing mesh and finished with stucco, it can hold tremendous weight. This is why Domes built in this manner work so well because their geometry works well at distributing loads across the cement air bubble lattice of the Aircrete while the tensile exoskeletal layers prevent outward expansion and lateral shearing.
I can poke a hole in raw Aircrete with my finger, and I can also drive a car on top of an Aircrete Dome after the tensile layers have been added while the inhabitants of that dome stay warm inside due to its rigid insulation properties while it is retaining a hillside and terracing land as it is partially earth buried.
@@WhistleLad The purpose of our testing was: to get a feel for aircrete and the process of making it, to compare the different mixes to each other so we could decide which recipe we wanted to use, and to see if we could produce a consistent and reasonably strong aircrete that wasn't overly brittle.
We aren't saying it can't be done, but we were not able to do it, and have seen many others struggle with making it themselves too.
It sounds like someone has figured out how to make some good and consistent aircrete, that sounds like an amazing dome. 👍🙂
@@RedandAprilOff-Grid I am suggesting that Aircrete is always brittle and that there is no way to change that because it is 70% air. The brittle factor can be reduced, but only at the expense of the air. More durable Aircrete will inevitably have less air bubbles in it, which will reduce its insulating properties. Different mixes serve different purposes and there are nearly an unlimited number of mixes that can be produced. Fiberglass or basalt chopped fibers can be mixed in, thickening agent and air entrainment can be introduced, but the end result will always be somewhat weak when the air ratio is >50%.
All of the blocks I make are brittle, but when they are stacked like an igloo and the dome walls of Aircrete are sandwiched between tensile reinforcement layers like basalt mesh the whole structure becomes incredibly strong.
The blocks themselves do not need to have tensile strength, nor shear strength, nor localized poking strength because they cannot move once within the outer shell of the mortared on reinforcement layers (basalt or fiberglass mesh) and because those tensile layers transfer loads down the geometry of the structure in a distributive way.
Surf boards 🏄♂️ are made of styrofoam a very brittle and easy to poke-thru substance, however, once the fiberglass resin layers are added to the exterior, surf boards 🏄♀️ become strong and durable. This is similar to how Aircrete is best used.
I am primarily explaining this for anyone who will read the comments. I understand that for your build you have now chosen a material that is better suited for your plans.
Sending you best wishes. We will each be in new homes very soon! Round or rectangular, home is where the heart is.
@@WhistleLad So what you're saying is that these test were like testing the strength of a surfboard before the surfboard is finished?
Hi in Jamaica we use a constant mix of 3sand 1cement 3gravel plus use 3/8 rebar Plus you can add starofom flakes for insulation
Yes, poured concrete is a great way to go. We considered it but decided we wanted more insulation, but with our overhangs and orientation I think it would have worked out pretty well. 🌞
I wouldn't use it for load bearing, but as an alternative insulation it would probably work well.
Yes, our supports were going to be 8 feet apart, so we were a bit worried about the aircrete having to span that large of a gap. Some of our batches were pretty nice and not powdery and brittle. The cold Drexel was likely a contributor to the issues with the later batches.
You guys gave it such a good shot and I am sorry it didn't work out. I look forward to seeing how the new house goes!
Thanks! 😊🏠
I understand that adding ground up Styrofoam makes aircrete stronger, more insulating, and easier to work with.
That's what they say, I'm interested to see more people building with it. Hopefully styrocrete homes will be popping up everywhere soon. 🙂🏠
add hemp - or straw
Did you add a wire frame within to prevent from cracking?
Aircrete is not good for load bearing unless the bricks are at least
12" ×12"×18". The best way to use it is within structural panels to serve as insulation. That's what seems to work the best. It can be used for domes because that shape is "self supporting".
What Is the load bearing capacity of it vs 2x4 pine and 2x6 pine?
Thanks for documenting this so others will know to not rely on aircrete as structural elements. This is why others use more structurally sound elements within or around the aircrete to compensate. Personally I think such compensations make aircrete a superior solution but your pivot worked well. Well done.
Our design was explained in previous videos. This was just one in the series.
I think it would be well worth your while to attend an aircrete workshop. I know both 'Aircrete Harry' and 'Domegaia' put these on. Harry also does consulting work at a very reasonable price. If you watch his videos, you'll see he went through all your issues and he has shown how he overcame them.
The workshops are pretty expensive. I also figure that a lot of the people who go through the workshops decide not to use aircrete, I'm just not seeing many people actually make or live in anything made out of aircrete. I watched most of aircrete Harry's videos, and anyone else talking about aircrete that I could find. I ordered Harry's thickening agent, and asked him some questions. He didn't answer my questions about how to get soft water, but we found an RV water softener that worked well. Giggedy George finally did a video detailing, what our main problem probably was, but by then it was too late. Our batches got worse as the temperatures dropped, it appears that using warm water in the Drexel solution likely would have helped. We have videos showing everything we tried. We had some great batches in the beginning, and go into foam density and other issues we dealt with in detail.
@@RedandAprilOff-Grid I think you were likely up against a few different things. I don't put a lot of stock into Quickcrete products. I watched another guy doing aircrete and he was using Bluebell or something then one time he got some Quickcrete and it was a disaster. The temperature is a huge factor too. Then even if everything goes right aircrete is still aircrete.
Have you tried long string hay mixed with aircrete? Fyi air Crete can only be used for non structural areas.
I can tell you exactly what you did wrong as far as the consistency of the aircrete is concerned. This is a mistake many make including me,very frustrating, so don't feel alone. Ignorance is NOT stupidity. The first time you start making aircrete there is a hesentincy to the mixing. As you do more, you naturally mix faster. To keep the small tight bubbles, foam size, it is extremely important that you mix at a very slow rate. Moving up and down, side to side. Never allowing the whirlpool effect to carry air into the mix. Mixing to fast also causes the foam to combine into larger bubbles and when taken to extreme the air crete will collapse during the curing. This is obvious when I watched this video and saw how the progression of the old to new bricks where laid out.
#2 The plans for your house are for the most part conventional. Aircrete in this case is only good as an insulator, not a structure. So you made the correct call changing your plans.
Beyond what I have to say you guys presented a awesome video of your experiences and I learned from it. Thank you so much for posting!
Aircrete is very finicky stuff, glad you figured out what worked. We tried all different types of mixing strategies, which can be seen in our other videos. I suspect that the cold Drexel was the problem with our later batches, but mixing speed may have contributed too. Best wishes on your aircrete projects! 🙂
Sorry for your frustrations!
I just came across this video and I am WAY late to the party. Haven’t read the comments from others. Just wanted to offer some information I learned some years ago when I was sold on rammed earth: it’s a method called PISE which is the acronym for “pneumatically impacted stabilized earth.” The system utilizes sheet goods (kind of needs to be plywood) as an inside-of-wall form against which is shot resident soil mixed with Portland cement and fiberglass shards and applied with a gunnite machine which introduced water at the nozzle.
I saw a residence and a winery office building done this way in Northern California and it actually passed building code with the addition of some rebar which the builder told me was totally unnecessary, but required here in earthquake country.
Sounds cool! Yes, once we couldn't find a tractor for a reasonable price, we backed out of rammed earth and decided to try aircrete, and when that didn't work, we went with wood and metal as the main materials for our DIY home build. 🏠🏜️
Red and April thank you for sharing your "real" journey. By you sharing your data and your outcomes (good and bad) is like learning right alongside you.
--So, as you have proven, Aircrete created with "foam" (foamcrete as I call it) is very fragile. It has its use in certain geodesic forms or non-domiciled structures, and hardfacing helps stability some (Honey Do Carpenter/The Happy Heresiarch) - but you really need chemically generated air bubbles for consistency and autoclaving to make aircrete somewhat durable. (Autoclaved Aerated Concrete = AAC - Think Hebel or Aercon AAC Blocks)
But DIY'ing AAC is prohibitively expensive - as autoclaves are. And purchasing AAC is also expensive and defeats the goal of self-sufficiency, IMHO.
You folks seem as if you've done your research, so I assume you know how extremely labor-intensive rammed earth really is.
--So my question to you is before you move on to rammed earth, had you considered these two alternatives?
--1) Creating polystyrene/cement blocks or panels instead of foamcrete? You may be able to create more durable blocks/panels for the walls in your home, that perform just as good - if not better than aircrete, simply by using recycled ground-up polystyrene beads and Portland cement with an ad-mix. (Think "The Perfect Block" out of Tucson - but without holes or need for the expensive grouting) Structural support would still come from your steel frame. Stephen Williams (Aircrete) - has a RUclips channel where he's built a structure in this manner.
--2) If you like the thought of truly using "earth" as the building material, had you considered compressed earth block for your home? It's still labor intensive but less so than rammed earth and it produces similar look/performance of rammed earth. "Sustainable Living" RUclips Channel
We gave it a good go, but aircrete is tricky stuff! We steered away from rammed earth because of the equipment needed, labor, and we wanted something that would be more insulative. Styrocrete looks interesting, but it is also untested, and looks pretty labor intensive and messy. Even if it's easy to shred, that's a whole lot of styrofoam to collect and deal with. We decided to go with a more traditional build, and found it won't cost us any more than aircrete, and it is going up much faster.
I just found your comment, sorry about the delay in responding. 🙂
@@RedandAprilOff-Grid im sure you know that cement cures through hydrolysis. Heat can speed up curing. But you need water. Too much water and your product can be weak, to little it never cures. You are very correct its hard to get consistent results as their are so many things out of your control. The humidity, heat, sun light, wind, other convection. Great luck in the future. Its better to get something done poorly then to keep thinking and never start it.
Styrofoam or polystyrene, aren't these toxic? Even from within the blocks? I read about health alerts...
Thanks for sharing your experiences, even if they didn't turn out the way you hoped.
Thanks! We had a really hard time finding answers to our aircrete questions, so we wanted to put it all out there for others to learn from. The good and the bad.
Perhaps aircrete is more suitable as an insulation material and not rely on structural capability at all.
It looks like your cement dried out too quickly, thats why the blocks are powdery, cement needs moisture for a few days to chemically cure.
When testing our first set of samples we watered them twice a day for 7 days. These last fiber samples were not kept as wet in the well house. They were just covered in plastic, which kept quite a bit of the moisture in but not as good as daily waterings. We could also tell right away that the samples had large bubbles and were more like our number 3 and 5 batches, so we weren't expecting great things out of them. Samples 3 and 5 we're also quite brittle because of the larger air pockets, even though they were cured properly. It might work okay for insulation, but the lighter mixes turn to powder with any rubbing or impact.
@@RedandAprilOff-Grid given all the headaches of foam with aircrete it's easier to use styrofoam which is easily gotten in larger cities and has R value of R2.5 vs 2.2 for air crete ruclips.net/video/6U4JAop0dTY/видео.html
@@khandam7709 It would require a whole lot of styrofoam, and I'm not sure that it's actually that easy to make or dependable in how it turns out. It will be interesting when more people start making stuff out of it and showing their results. We are not near a big city, don't have a big shop to store and shred massive amounts of styrofoam, and I would rather not have our vehicle and property covered in styrofoam bits.
@@RedandAprilOff-Grid You are very thorough in your experiments.
The only other thing I could think of to improve the blocks would be to line each block mold with a sheet of housewrap or similar material so that you get the effect of drywall, as the plaster powder in drywall is very brittle and requires the paper both sides to give it strength.
Maybe other fabrics would work, if they are able to hold moisture and not shed it like housewrap it could be dipped in a bonding agent to help glue it to the block, but then your mold would have to be polycarb or some other rigid plastc, and the blocks would have to be big in order to make it worthwhile to go to all that trouble.
Going for a coating solution rather than an additive could work out cheaper than mixing a substance all the way through when just strengthening the outside of the block is required.
So , have you ever changed the formula? I just watched it on RUclips, they use very small amounts of cement. They produce it with a large amount of lime and much thicker than this.
Graphene-enhanced concrete is tested and it provides a 146% increase in compressive strength, a 70% increase in flexural strength, and a 400% decrease in permeability. The incorporation of graphene in concrete would develop structures with increased durability, an increased conductivity, and thermal properties. Resulting in an overall decrease in CO2 emissions.
Hemp concrete or hemp lime, it's a biocomposite made from a mix of the woody core of the hemp plant, lime binder, and water. The hemp core (also hemp hurd or shiv) has a high silica content that allows it to strongly bind with the lime.. As a result, you get a lightweight, cementitious material with good high insulation properties that weighs six to eight times less than concrete. It's ability to aborb CO2 emissions actually make it a carbon negative product. Because of the high moisture content care must be taken in the drying or curing of hemp, unless your intention is to make hemp graphene. At this time hemp is available in moderate amounts except for industrial or textile use and is utilized in a variety of products from clothing and shoes to bulletproof vests, car parts, artesian niche soaps, oils, beauty and health products. For hundreds of years it has been available as rope for maritime travel in boats and netting. Hemp as a means of paper and due to it's strength even the paper is utilzed to make implements, dishes, cups and musical instruments.
Aircrete is simply concrete with bubbles., there is no set formula. Fine foam, which has a high density, can be added to increase aerated concrete's strength, which results in a stronger aircrete. When high densities of foam are included, aircrete can become brittle, and chipping can occur. This type of aircrete will have limited compressive strength and could not be load-bearing.Aircrete offers many traditional concrete benefits with added properties to enhance sustainable and energy-efficient homes. Aircrete offers superior insulation properties due to foam and air bubbles built into concrete itself which can be enhanced by adding various types of polystyrene or polyurethane foams improving it's insulation values.Aircrete is most often used for exterior and interior walls. However, aircrete can also be used for several other home applications, such as precast blocks and panels and concrete slabs for an insulated flooring system. In some cases aircrete is used for poured roofs, increasing insulation capacity of ceilings and attics where heat tends to escape from homes. When used with additives it's load bearing capabiities, compressive strength, durabilities and other characteristics are greatly enhanced.
The availability, cost, and labor of different aircrete add-ins was our main consideration. I have seen people experimenting with using graphine in aircrete, but it seems to be hard to get in a usable and affordable form. Adding styrofoam looks interesting, but the logistics, method, and tremendous amount of space and styrofoam that would be required to build a home are a couple of things that steered us away from it.
Red adjusted the air pressure some for the colder temperatures, but I think our foam was still more dense than it was earlier so I figure that's why our batches were getting more brittle.
Now that the cost of lumber has come down some, it is actually less expensive to build a more traditional house than one out of aircrete. Aircrete would have made a more interesting house, but we didn't want to wait 5 months before we could try again.
Good info! 😎👍
@@RedandAprilOff-Grid it's cheap to make graphene and it can be made from most anything including sugar. Aluminum powder limestone powder and polystyrene is cheap.Basic recipe for non-autoclaved lightweight aerated concrete (aircrete) with 600lbs kg/m3 density:
-Ordinary Portland cement
-Limestone powder (particles up to 0.05 mm)
-Aluminum powder MEPCO 7520 or any Aluminum powder with blaine value 15,000 cm2/g and more
Dry mix formula:
50% cement (by weight) + 50% limestone powder. For 1 kg of dry mix you need 500g cement and 500g limestone powder
Mixture formula for for 700kg/m3 density:
1 kg of dry mix0.65 liters of water, 1 g of aluminum powder for 100 kg of dry mix you will 65 liters of water and 100 g of aluminum powder.
How to mix it:
1. Add water in the bucket.
2. Add dry mix in the water and mix it for a couple of minutes.
3. Add aluminum powder and mix 1-2 minutes.
4. Check video for graphene dry mix ratio and add
5. Pour in mold.
Videos are on RUclips.
@@nwflboy007powell8 Sounds interesting! 👍🙂
Did you use a good quality former with a professional grade foaming agent? Measured by weight? I have never seen such quality deviations like you had. What did you use? Dish soap?
We used Drexel. We were testing different recipes, and have other videos explaining all of that.
Question . How long did you let it cure ? You have to let it sit for 28 days to fully cure . And it's best to keep it wet . And shaded . Harsh sun will burn green Crete . Making it powder .
This video sums up pretty well our methods of making the aircrete and testing process. ruclips.net/video/LjmU4T3aAWw/видео.html
Thank you for showing the reality of aircrete. I commented in your other video that I used perlite, it is rock bubbles so there is no inconsistency in the air bubbles because they are already bubbles incased in rock when you get the perlite. I also sandwiched the lightweight concrete with fiber stucco to give it hard surface. Where are you located that you can do builds like this? Rural Texas?
I will also say if you are willing to spend lots and lots of time building, they are many options. My idea was a method that is not labor intensive, but only time intensive using forms to create arches. You can only pour one arch at a time, and then wait days for it to harden enough to do the next one, and 50 arches then takes a long time....but not a lot of labor, and it would scale if you have multiple forms.
We are in Cochise County, Arizona and have an owner builder opt out permit, so we thought it would be fun to try something different. It was an experience and made us appreciated regular construction materials even more. We liked the idea of just adding bubbles, because it would be less materials to buy and deal with. We were so glad, we changed plans, and love that our house is very energy efficient, and almost completely passive. The arches sound pretty cool! 👍🌞
Thanks for sharing your experience.
Perhaps it is not meant to have supporting features, as columns or beams,
Perhaps to be used on the floor only, as screed?
Would you agree?
Aircrete does not have good compressive strength and needs to be supported, which also makes it not good for floors. There are cheaper and much easier ways to insulate a floor or walls. We insulated our earthen and concrete floors with rigid foam board.
@@RedandAprilOff-Grid thanx
What about autoclaving ? Would that have made them more sturdy ?
Is this not the same as foamcrete? Where the use of dish soap is applied. That is to say, are the two dishcrete enough in significance to merit speaking of in different ways? Harhar.
It sucks to invest time and money in a building system only to have to abandon it. Hopefully your experience will spare others from that experience. Thanks for sharing!
Yes, we are so glad we didn't use aircrete! It's more expensive and a lot more work. We love how our passive house turned out.
Most intriguing, I’ve made a hundred honey bee boxes from aircrete but mixed with sheep wool for humidity regulation, but this was done by a pro with my moulds and I finished them of with micro cement
Wow, that's awesome!
2:05 I am not a fan of aircrete. But this is clearly user error. All concrete has low tensile strength and high compression strength. That test is for tensile strength. Either reinforce it or use a different material for the parts of the house where you need tensile strength.
The testing was to compare the samples and different recipes against each other, as well as our ability to make good consistent batches, to determine if we wanted to build our house out of it. We were definitely going to reinforce it, this was just one video in the series.
Sorry it didn't work out after all your effort. Was wondering if you did anything to your foam gun like seeing if the stainless steel scrubbers were compressed?
Thanks, no we haven't looked at it. The temperatures were starting to get below freezing, so we figure that was probably a factor. Aircrete would have been such a pain, I'm really glad we didn't try to use it.
You folks are an inspiration. I have been testing mixes of portand cement and native soil here. I have found a 3/1 mix of screened soil is really good stuff here. Thanks!
Awesome! We were considering trying to make a batch with dirt, but our soil varies widely. We have it all, silt, clay and sand, so we figured it would be hard to get a consistent product since we would need a lot. Sifting the sand through a fine mesh for our test batch was sure was a lot of work, but it did make a good strong aircrete. Thanks for watching! 😊
@@RedandAprilOff-Grid you should mix the soils you determine to use until they are uniform.
...how about the weather/humidity/temperature, over the months of your tests? Would it be a significant external variable?
I think the colder temperatures were likely contributing to the issues with the later batches, but there may have been other factors too which just makes aircrete overall not a good option for us out here in the desert. We have big temperature swings from day to night, and are typically very dry. We kept the samples covered and watered them twice a day, but not much else we could do to control the environment.
Really enlightening, sure appreciate you hard work.
Super helpful to know! Thanks so much for the warning!
Glad it was helpful! I know some people say aircrete is great, but we think there are much better and easier options for the same or less cost.
could you use the self repairing concrete Bactria in it? so when it gets wet it fills in the gaps?
Don't know much about it.
did you add metal reinforcement rebar/Concrete Remesh in the mold/forms? also did you vibrate or hit the outside of the forms to get the concrete to get the cascades out of the mold surface? I also think if you add some portland cement to the mix I feel it should have come out better
This video will answer some of your questions, ruclips.net/video/42z8k8Y-zf0/видео.html we also have a playlist.
@@RedandAprilOff-Grid I watched your video to strengthen concrete you need to add fiberglass chop strands none of the wire you used was strong enough you need to add 3 pieces of number 3# rebar or 2 pieces of number 4# rebar the wire you used did not have any linear strength I am not sure of the formula but you need to add ready mix with your aircrete or add rocks and sand to it to add strength I will see if a friend of mind has a formula for mixing but you need to add fiberglass or rebar to make you casing strong I feel you need to get the right mix and add rebar your footing pour don't have any strength and you could take a mall and crack without much effort
How did you guys learn this? Did you take a workshop. Did you try different soap? Did you make a homemade foamer. I found it verys alot if your foaming machine is tweaked one way or the other.
The first two videos in our playlist, should answer most of your questions. 🌞 ruclips.net/p/PLW_v9VWGwCM_gdAXzuKTr8J13rTZ1DSpx
Did you guys tried to apply helix micro rebar with your aircreate to reinforce the base material?
No, we didn't try it. Someone mentioned that if fibers are not fully encased in the material, they are not very effective. Which makes sense.
It was getting too cold to continue testing, and that's also likely why out later batches were turning out so poorly. Aircrete seems to be pretty temperature sensitive, which also makes it a difficult material to build with.
I'm going with cinder blocks. Not sure how I'll dress the exterior, but I have time to figure it out.
I applaud you all for taking on building your own home. Seems to me you took on a course in materials science and engineering, without having an instructor to help you know the chemistry and physics principles in play to explain what you experienced and figure out how to make changes to get what you want.
I agree with commenters who made a point about the environmental changes (due to weather) that impacted your results with the aircrete blocks. There are chemistry and physics principles at play that commercial operations tightly control so they get consistency in production variables. Your experiments show how sensitive materials can be to the environment.
I wish you well with your new approach and hope the result is all you want it to be!
Thanks! We also learned that aircrete isn't an inexpensive material to build with. The house we built was easier, and less expensive. It's also heated completely passively in the winter from the sun. We are very glad we didn't use aircrete. 🌞🏡 🏜️
I've often wondered why one can not use a drier foam. So higher air pressure. Then you mix the cement slurry, and then start mixing in the foam by fixed water volume. Then keep mixing until the volume reduces to the calculated volume. I am sure that longer mixing will pull the extra air out. Then one will end with a given amount of cement and water and aim for a target volume instead of hunting the foam density. Can this not work? I also think that adding a cup of Bentonite clay in stead of Glycerine, will get the mix smoother and help to trap smaller bubbles. Bentonite is a ultra fine clay that chemically reacts with the cement on curing. So the product should be harder. Cat litter is often Bentonite. Not always.
We know what happens when the foam is too wet, but I'm not sure what happens when it's dry. Maybe worth a try, aircrete is tricky stuff.
@@RedandAprilOff-Grid It is worth a try. As long as it is not freezing, temp is no issue with cement curing. It may affect the foam density though.. I am planning on building a Gothic Artch house here in Sweden next year. So Aircrete. I want to pour directly rather than make and use bricks. Also a good and easy coating is cement and salt, 50 50 and water to the desired viscosity. hardens the outer surface and can be used with fabric. I apply it with a soft broom.
@@heikkiparviainen6084 That sounds awesome! Best wishes on your build! Aircrete is tricky stuff, but I'm sure it's possible to get it right. We still need to finish the plaster on the garden wall, we might give that recipe a try. Maybe the salt would keep it from freezing. We tried to keep it protected, but the plaster on the first section has white patches where it froze.
I appreciate Tiny Giant Lifestyle YT channel on aircrete, as he demonstrates that micro-cracks are a non-issue if you apply reinforcing mesh on both sides, and this also eliminates the strength concerns. If you have a rigid frame and are using aircrete to fill in the blanks, how much stronger than rigid foam does it really need to be?
We were planning to add mesh and reinforcements, but decided we still didn't trust it to last 50+ years. Even autoclave only has a 30 year lifespan, which isn't great. Once it starts crumbling it turns to powder and it can't be repaired. We decided there are, better, cheaper and easier materials to work with.
Did you check out the concrete block mixed with foam. It's supposedly very strong and highly energy efficient.
Looks interesting, but we would need a whole lot of styrofoam to build a house, and it's still a homemade product that still needs a lot of testing.
@@RedandAprilOff-Grid you can buy the Styrofoam pellets by the bag. I think you can also buy the blocks. The blocks interlock, and you stack them dry, then you push the rebar through the holes, then fill with slump.
Were you making it in cold weather and what was the humidity warmer less humidity works better
It was in the fall and just starting to get close to freezing. Yes, we suspect the water and Drexel were too cold, and the curing temperatures weren't ideal either. Most of the year is dry here.
I heard that mixing some fiberglass helps with strength. Whats your experience/mix with fiberglass?
It wasn't great. Someone mentioned in the comments, that the fibers need to be encased in a solid material for them to have much benefit. With the holes and overall weaknesses of the aircrete we tried them in, the fibers didn't seem to help much. In a lower foam mix with smaller bubbles, there would likely be some benefit.
Were you able to control the temperature and humidity during curing?
When we made our first batches, we were in the low 80s in the day and getting down into the mid 30s at night. We kept the samples wet and covered in plastic for 7 days. The last batches we had to let cure in our well house to keep them from freezing. I suspect the cold Drexel was our main problem with later batches. It wouldn't have been practical in our situation, but using warm water may have helped.
It had occasion to talk with the folks that have been making it commercially for 50 years in Europe when they tried to move into U.S.markets. There were two key things that they did. #1was that they mixed aluminum powder that slowly gave off tiny bubbles as it reacted, so it poured into molds without bubbles and then rose like baking a cake. Then once it roseto the desired amount the mold was heated to speed and finish the chemistry that gives concrete its strength. I still have the sample in I use as a trivia on the stove. It never gets hard against abrasion like regular concrete ( being able to cut it with a handsaw is considered a feature) an will always need protection from abrasion, but it does not fall apart like your sample.
As I suspect that the change in quality might have been due to temperature as much as anything else (and the original invention was in Sweden) that would be a good reason to run steam along the outside of the mold.
😎 Yes, this is more of a DIY method. It makes aircrete but a lot can go wrong and the results can be inconsistent.
I suspect the the colder temperatures were affecting the foam, and using warm water in the soap solution may have helped. 🌞
@@RedandAprilOff-Grid the fine aluminum powder used for fake guilding is readily available, and the water/concrete mix makes a big difference in strength, but keeping the result as close to 180 f is the critical difference I think. I did not think so at that time but by doing that they got consistently even more than specific strength. Metal molds would not be that hard and a way to have the steam run underneath even at normal pressures and even just doing that alone would give better results than the best you got, and the difference affect you as long as you lived there. Using just warm water or even hot water would cool too fast, The chemical reaction can take several days in the best of circumstances which is why they wait si long to build the next floor.
I'm curious if you tried to control your drying environment- humidity and dry-bulb temperature?
All samples were watered twice daily and kept covered and wet for 8 days before testing. We were not able to control the temperature, and it was likely a factor when making the last few batches of aircrete.
Thank you for sharing this valuable work. you have saved me from tons of work and money.
We didn't quite get it figured out. It's tricky stuff, and overall a big pain to make. Our best guess is that the colder temperatures were causing our later batches to fail. Thanks for watching! 🙂
Siporex is widely used in France. Is Autoclaved Aerated Concrete the US equivalent ?
Interesting, I don't know much about either.
Have you tried adding structural support like rebar?
We were planning to add wire mesh or some other kind of metal support, and also fiberglass fabric and plaster on the inside and outside. Our testing was to compare the different aircrete batches against each other, and see if we could make consistent batches. I tend to think now, that the wire support would eventually make the cracking worse. Our garden wall shows significant shrinkage and cracking.
Thank you for making this video. How long did you let the test samples cure for before testing them?
They were wet cured for 7 days, and then tested wet. We figured with a standing wall it wasn't going to be possible to keep it wet for a full 3 weeks, and the tests were to compare the different recipes and our ability to make them.
You are welcome, hope you can learn something useful from it. Here is our aircrete videos playlist ruclips.net/p/PLW_v9VWGwCM_gdAXzuKTr8J13rTZ1DSpx
Just a bit late to add a comment question..
But just wondering if you had similar experience i had in Western Australia..
My first samples were stable and strong..
Some failed miserably when i tried getting more volume by increased foam and less portland cement..
But I had total failure of the next lot and couldn't for the life of me work out why..
Some investing i find not all Portland Cement is equall on the market and this particular one had refractory ash added in very low % but seemed to be the killer...
There was a shortage at the time we were doing this, so we ended up using various brands of portland cement. It was hard to tell, if there was much difference between them. We decided there were too many variables, temperature was also an issue. Our winters are cold, and we didn't want to wait until spring. 🌞🏜️
I worked for a roof and roof deck company back in the 90's. We used "light gage metal cee's" to make trusses for schools, Structural Engineer designed and all that. However, these weren't the 24 or 26 gage cees used for interior, non load bearing walls. These were up to 10 gage, mostly 12-16 gage.
The gage you need depends on the distance you want to span. We bolted two 9 inch cee purlins back to back to make 25ft I beams for our roof trusses.
Did you try to submerge blocks in water for 2 to 4 weeks to slow down curing?
We covered them well with plastic and wet them down 2× a day. We knew on our house we weren't going to be able to keep the aircrete wet for more than a week without lots of forms and big expense.
@@RedandAprilOff-Grid Totally understand the limitations of resources for this kind of thing is a spammer in the works. Just the inconsistencies of the many tests must really frustrate you. Hope you are getting better results with new materials. Inspiring. 👍👍
@@Joburgbass Thanks! Yes, our house turned out great. It was less expensive, and much less frustrating to build.
How about plying AIRCRETE outside of the shipping container?!!
That would be interesting. 🙂
I've done some testing myself and your foam concrete looks like is doesn't use enough sand.
What I've done to make it more durable and reduce big air bubbles was to increase the tenside amount and foam it to 30g a litre. I also increased the amount of sand but used very small construction sand. I also added hemp fibres to it. The resulting bricks behave like hard plastic. The denser foam can hold the smaller sand much better and hemp fibres gave extra support.
If you need tensile strength you need to add a large mesh structure of some kind, small shredded fibres dont help much and can even make it more brittle. You need long intertwined organic fibres or a glassfibre/metal mesh or similar.
If you want to cheap out and have an easier build I'd use earthbags instead of foamconcrete. Foamconcrete is hard to make and needs exp. or one needs to follow a recipe exactly for it to be good.
Glad you found something that worked. Aircrete is tricky stuff. Some of our earlier batches turned out really well. We have videos showing the methods we used, and different things we added and tried. We suspect the colder temperatures were the main issue with our later batches, but there were probably other contributing factors. Regular aircrete doesn't have sand, but we tried some batches with finely sifted sand, it almost worked. It had awesome compressive strength, but the batch fell slightly, and sifting the sand was a lot of work, and it was heavy and hard to mix. Best wishes on your aircrete projects! 😎
Did you test the alkalanity/acidity of your water? I feel your issue is related to something in your locality if you’re assured you followed the mixing instructions as given. I trust a perspective shift might benifit your process outcome. Cheers!
We used our well water and a portable water softener. Once we got the hang of it, our first batches turned out great. We figure the colder temperatures were to blame for the batches getting worse. Maybe it's possible to get good consistent batches if you are working indoors, it have a nice long spell of ideal temperatures. We are glad we moved on from aircrete, and we should be done with our house in a few weeks. 🙂🏜️
100% agree with your conclusion, heat and cold cycles would have caused cracks and separation.
Would using a concrete vibratory diminish the effectiveness of the aircrete?
When the batch turns out right it fills the form in nicely. The main reason for air pockets is overmixing, a leak, or an unsuccessful batch where too many air bubbles pop, and you end up with voids.
As a residential designer that specifies the materials on house and addition projects I hear from customers interested in all sorts of building systems. A lot of folks lock onto a particular system as the answer for their dream home and I always need to ask what the question is that material answers. It's really easy for people to get caught up on the miracle system that does it all but the choice needs to be based on the sum of a bunch of questions. What is the local climate and what are the site risks, what is the ability of the client to pay, what kind of materials are locally available and meet the clients desires and finances, what are the local trades capable of doing with proven competence are a few of the issues, and there are a bunch of other questions that need to be answered. I have never gotten to build in the desert but if somebody offered me a project on a big lot in an arid place I'd start by looking at what the locals have been doing for the last thousand or so years. If you want low carbon and low embodied energy you're going to minimize concrete, styrofoam and steel. If longevity, healthfulness and sustainability are important then start thinking adobe or rammed earth at a site like this. Wood is good.
Aircrete sounded interesting, and people were saying it was less expensive and had a lot of insulation value. It turned out that neither were true. We are so glad we went with something different. Out house is performing amazingly well and is heated completely from the sun, and with our cool nights a simple evaporative cooler works great in the summer. Our son is currently building a hyperadobe house. It's pretty cool. We are currently sharing his build on our channel. 🌞🏜️
Temperature's surely could be a factor. Maybe in a stable environment, same temps, etc the results would be the same. Thanks for sharing the information.
Are the challenges related to changes in ambient air temperature ?
That is quite possible, the Drexel foaming agent says on the label that it need to be used at room temperature, and our RV was getting pretty cold at night. We tried setting it out in the sun in the morning, but it was still pretty cold, and our well water was real cold too.
cant you like put a thin lining of clear epoxy on all exposed surface? Inside it could help design and any hardener for surfaces would work.
I'm not sure? Typically aircrete is covered in a sturdy cloth or fiberglass netting, and then plastered.
Excellent video, What kinds software , Did you use for plan? You worked as professionals like Architects and Engineer
He used Chief Architect, they have a monthly subscription option. Red has a Bachelor's degree in Business Administration. Woodworking and building have been a hobby of his for a long time.
@@RedandAprilOff-Grid Great
Can you tell me which workshop you attended? I’m looking at attending one but want to choose one wisely.
We did not attend workshop.
why not regular concrete?
We considered it, but the drawback is that it has very little insulative value, but it is great for thermal mass.
My first suspect from what you are saying and your inability at replication or improvement through ingredients would be hydration, mainly because you did not mention it yet it is one of the most important factors in strengthening concrete. How did you hydrate this during curing and for how long did you cure it ? Did you keep it covered during hydration / curing ? Did you use any plasticizers or water reducers or additives like fly ash, slag or silica fume ?
It was all explained in previous videos. The samples were all treated the same, covered in plastic, and watered morning and night for 7 days. Then we tested them on the 8th day to compare the different batches and recipes.
We looked for somewhere to buy fly ash, but we couldn't find anyone that would sell it to us. The recipe we used, is in the description of all of our aircrete videos.
Hi Red & April. I followed along of most of your aircrete vids. Others too here.. ive never liked the folding in of the cement into the foam. What if your paddle mixer was 4 very fine sieves and the dry cement was mixed into the foam. The tiny holes in the sieves would continually aerate the mix as long as you need. Great series of vids. Thanks.
the dry cement would pop the bubbles
From what I understand, cement needs to be fully saturated with water to set up properly. When mixing in the foam, if dry cement is still stuck on the sides of the barrel it causes problems. But you never know, it might work. Thanks for watching! 😊
I am no architect but I have worked construction for quite a few years on your c Channel trusses you should be fine just using them as is look up how much load it can actually Handle by the thickness of it and how long it is another thing to think about is you should put wood purlins on it so you can attach the metal sheeting you also want to put a vapor barrier between the metal in the wood to keep down wrought and good way to attach the wood to your c channel is a Ramset make sure you get the right 27 caliber charge but this will be quicker than using screws because you literally just push it up against the wood and pull the trigger screws will burn out and drill bits will burn up it's a very cost-effective way to attach wood to metal but make sure you only use this against heavy metal not the sheathing it will just blow a hole through the sheathing
He already ordered some special screws for it, but the Ramset sounds interesting, he'll look it up. 👍🙂
If I were making a tiny retirement house in the high desert, I'd just go with cinder block. For coolness, I'd make an extra-high ceiling and tile floor. Can always cover it with a rug in the winter. Two stories might be best: appliances and summer sleeping downstairs, winter bedroom upstairs. But then as you get older, you won't want stairs. Anyway best of luck.
Because of the extreme temperatures we get here, we wanted to build a house with good insulation. We ended up going with 2×4 framing but we added exterior insulation. Along with the passive design and thermal mass our house is heated entirely from the sun in the winter. The stable even temperatures are amazing! Thanks! 🌞🏜️
We have urban/ wild land interface fire codes here so any new construction or window replacement needs to comply. At least one tempered glass pane in an insulated glass panel. Easy to order from major window and door manufacturers. Siding can be stucco, cement board or metal. Try to skip the rigid foam since it is extremely flammable. Rock wool is expensive but fireproof.
We used metal siding, so there's not much risk of fire. The complete envelope around the entire house as well as the reflective properties of the foam board have worked out amazingly well. We also added a lot of thermal mass on the inside, so our house maintains its temperature really well.