I really appreciate the detail and clarity you go into with this entire channel, mistakes and hiccups especially. Your honesty about problems and mistakes are one of the most useful parts and makes the channel a great resource. I think your home is a bit of a moonshot, but I'm glad you are documenting it so completely.
Looking good. I must say, your website is much more comprehensive than I expected. You have done a great job researching! I'm very interested in learning more as the house is completed and you continue to share new developments. Thank you for sharing!
This is one of the most interesting builds I've seen, and it looks like you guys are hard workers, enjoyed watching all of your vids, thanks for taking the time to do this so others can see how much work and time it takes to do something this complicated . Thx again !!!
I've wanted to do the same project and my thought was, shot create and then covered with pond liner not sure the cost deference between pond liner and water proofing but I I would think the pond liner would have the potential for lasting longer... great project and you guys are doing a killer job. 👏👏
Wow I really like what you built. If you like it and the family likes it well that’s all that matters. I’ve been in construction for a while and every one seems to be an expert. It’s amazing who will toss around comments and I bet they never built anything outside the norm. God bless 🙏.
How thick will the layer of earth be on the sides? Just asking because wondering about the solution you have got in mind for the sidewindows, to get daylight in. And How they will hold up the earth above, cause the rooflights make the Impression that the earthlayer will be pretty substantial. Great project by the way. It makes it clear why everyone is building straigt walls, its just faster/less work and more preprocessed solutions on the market. So respect for the extra effort to make it that special. Curvature on the roof is a different Story, thats totaly perfect in terms of loadbearing. Keep on rocking.
I wonder if you would have went to big box store and bought all their "oops" outdoor latex paint and sprayed it over the waterproofing. It should have stuck well and the heavy pigmentation should block UV very well. It will eventually be covered so the color is not important. I used to do that to the inside of boats when I was rebuilding rotten floors and sterns.
There is a whole bunch more footage on my computer waiting to be edited down into something watchable, but we are not quite finished. I just buried 2/3rds of it this week and you see more about that on Facebook (more up to date) facebook.com/HomeintheEarth/ And yes, I would also like to see it finished.
I am shocked on what the waterproofing costs! Last week I had to repair an old asphalt roofing as it was leaking and I did so with a kind of liquid tar/rubber material that came in buckets. It cost me about 10 USD for 20kg bucket. This is for waterproofing roofs.. out of the bucket it has the consistency of a thick yelly and can be brushed on or rolled on, after drying it is like a rubber coat. So this is why I am shocked about the pricing you mentioned. I cant compare the quality of the products but seeing it usage and the problems you had with filling in rough concrete and then worries about UV destabilization, i feel the product I am referring to would do a better job for a fraction of the price. If you are interested in details then let me know, I have the empty bucket still around and can send you an image for reference.
Yea, sure. I would love to know what it is. My guess is that it is the sort of "damp" proofing that wouldn't work well enough for my application, but I would be happy to find a cheaper solution than the Blue Max.
That coating put on early was actually a good idea if water would have leached into the concrete cracks and froze it would have been a bigger issue later on.
I am not very familiar with concrete work but the finish looks very rough. Way to rough in my opinion. What kind of material is this? Is this kind of finish typical for it? The second thing is, I have often seen workers are spraying water on the structure to cause slow drying to prevent cracks and shrinkage. Does this technique not work with your material? Great project by the way! Thumb up left!
Yes, it is very rough. Normally a crew would have a few guys to apply the shotcrete and then a few more to come behind them and cut it smooth. When this job was done, they often came out with only the first 3 guys. Since then, I have not let this crew come back unless they can bring the finishing guys. The material is "shotcrete". It is a 7 sack mix with fly ash and pea stone rated at something like 8900 psi compressive strength. Yes, keeping it wet for a week (or waterproofing it right away) allows concrete to cure better and stronger.
This liquid rubber is actually waterproof... So waterproof that you could even put it on the inside (although outside is much better). It is elastic, so it can stretch to cover any cracks that form. And it is smooth and clean so we can climb on it later. On the other hand, Tar has not flexibility and will open up along any cracks that form under it (concrete always cracks somewhere). It also doesn't really stop water, under pressure, it just slows it down. Tar is actually classified as "damp proofing". Tar is also dirty and smelly and not something we would want on our job site when we need to climb on the roof so often. It is used so dominantly just because it is cheap and the people who are applying it do not have to live in the house. For earth sheltered homes, you just can't take that risk.
Good deal. With the UV damage did you end up adding an additional layer before burying the structure? I love following the project but my only fear has always been water getting in.
Sad to say it still isn't buried... Most of the footage in this clip was from nearly a year ago, but those last few video clips were from Monday night. We need that one last round of shotcrete (one day's work) to close off that roof section and finish the dormer eyebrows before we can bury it, and we just have not been able to get a crew out this year. Just not enough of them around and doing pools is easier money. When we are ready to bury, I will re-assess the damage and decide what to do. I am concerned that simply adding another layer won't work because it will stick to the UV damaged surface and not properly bond to the rubber or concrete below. Sort of like painting over rust. Maybe if I power wash it first...? Anyway, I am sure we'll figure it out.
I'd probably have put a pond liner over it and used that rubber stuff only for the ceiling lights. Connect the pond liner (epdm) to the rubber stuff with some hardcore glue like Innotec (even dries under water)... That pond liner stuff made from epdm is extremely durable and you don't have to worry about all cracks nstuff, only about whereever you have stuff going through it... Or use some bitumen coating/mats... but that rubber stuff.. no. I don't think that was a good option given your situation where time is a problem.
Yup, I also have a pond liner (my excavator gave me) and a bunch of used billboard vinyls (17 mil reinforced)... I'll be using all of those and more to make sure this all stays dry. This blue max is just the first layer.
It was budgeted at something in the seventy something dollars per square ft range. I think it might end up closer to ninety by the time we are done (some things, especially shotcrete, went over budget). The garage was 28$/sqft with the bathroom and electrical and waterproofing
Yes, that is my most likely solution. I will be needing to waterproof the new areas anyway, so it will be minimal extra work to just re-hit the worst affected areas while we are at it.
Yup, it can be a challenge if the problem is now under 10 ft of dirt. But there are plans for everything. Ask about a more specific repair and I will try to give a more specific comment.
We considered it, but moving those around, getting the waterproofing out, etc. seemed too inconvenient for the savings. We are not on the industrial enough scale for that.
Yea, they also sell those even larger 275 gallon totes for an even better price per gallon, and it has a tap so you could get it out into a smaller bucket easily, but that is just much more of this stuff than we thought we needed at the time.
since you have to recoat have you thought of contacting them and seeing about working out a promo video for a discount with your project I would think they would be interested in more exposure
thanks for video guys ill be using an epoxy or poly basically bed liner from this company linerxtreeme very good product and not a water somethings are just not best made with h20
Just because something is water based initially, doesn't mean it is soluble in water after the chemistry does its thing. But yea, there are lots of great coatings out there. You just need to balance a bunch of competing parameters and choose what works for you.
Uhm, ya’ll know you should paint over Blue Max as soon as possible, right? Don’t wait for the dirt to protect it. Every project has delays, so break the work into stages you can complete quickly.
If your shptcrete is shot properly by pros it shouldnt sag especialy when it isnt over 6 inch thick .after 6 inchs u have to consider another layer cage of rebar
shotcrete was the wrong way to go, aircrete with a kappa applicator would have saved you a heap O dough , I could see using shotcrete on the inside but even that I would have used a 25 lb spray scoop not tryin to be critical but your finishers were horrible
Looked up the engineering properties of aircrete and it is not nearly strong enough for my application. Like hemp crete or other non-standard "cretes", it has lots of fans, but is not the "way to go" for anyone relying on it to hold back serious earth loads. I had planned to use it to fill the the spaces between my shotcrete vaults (fill the space with insulating concrete that doesn't add a lot of weight), but there was no one really doing it in my area willing to bid on the job (there was one terrible company using it to repair flat roof commercial buildings). I also looked into buying my own equipment, but eventually (for a number of practical reasons) decided it was not the "way to go".
No offense, but who ever did your shotcrete did a poor job. I watched previous videos, and they basically flowed it in. If, instead, they had applied the shotcrete in 1/2 inch layers, allowing them to set, not cure, but set, between each layer, you would have had the same strength without the waste and gapping around openings. Trowelling after shooting, will actually cause the shotcrete to flow or sag when sprayed on that thick. This will not affect the cured strength of the concrete.Depending upon the area sprayed, they could have done a layer in the morning with a second layer in the afternoon, repeating the process until you've reached the desired thickness. Because of this, unless it is a large build, you cannot use a ready mix delivered and must use a batch mix, mixed on site.Correctly applied shotcrete will be applied as if you are spraying a heavy paint, too much and it runs (fallout), too little and you don't get even coverage. If you're worried about X-raying with the rebar showing through the finished concrete, simply use a grass whip to scrape the exterior rebar between sprayings. To prevent slumping at the base, put two rebar around the base of the vertical rebar and fill it first, scraping the base rings with a grass whip.You will need to use certain plasticizers to get a slump without the water content. Basically a plasticizer is a type of soap that allows the slump, without the excess water. To test if you have the correct slump, take a hoe scraper, looks like a straight hoe, scoop up some cement and with the face held horizontal, tap it several times till you reach the thickness you are spraying. You should then be able to turn the hoe scraper face vertical and the cement should remain on the face. I am very interested in doing what you've done. I'd like to do it from the inside, spraying it first with 3 inches of 2 lb. closed cell polyurethane foam, then hanging the rebar and spraying shotcrete on the inside. With concrete on the inside you get a thermal battery that once warmed or cooled, as the season directs, you will have about a 70% to 80% energy savings. Hope this helps other who may want to try your build.
There is the theoretical and there is what you can actually get done. I appreciate your comment to help anyone else planning to do likewise, this is why I film and comment so openly about my own journey. Here are some of my "realities" related to your comments. 1) Shotcrete crews prefer easier jobs to difficult ones. The crew was simply not willing to drag a heavy hose back and forth to do thin layers, I could barely get them to move it if they were overloading one half of an arch. Maybe that means I should have hired a different crew, but keep in mind that I couldn't even get another crew to come and give me a quote. There is too much work and it is too easy for the crews to turn down a "difficult" GC and take an easier job (such as a pool). If you want to get it done, some times you need to compromise a little. My original plans did call for most of what you are describing. I wanted things shot from the inside and finished nicely. No crew (including the one I did hire) would take on that work. Gunite crews will mix on site, but I don't know of any shotcrete crews that would do that when it is so much easier to just order a mix delivered. 2) They come with their own methods. I also knew lots of things about how shotcrete "should" be applied. If you find a crew that is willing to do it your way instead of their own way, I would be very surprised. Most of the time, you can expect to tell them what to do, but it is considerably more difficult if you try to tell them how to do it. If you try that before they on site, you may find they just take an easier job and never show up. You may find that you will need to do it yourself if you want it done a very specific way.
Several people have suggested I should get a crew experienced in "monolithic dome building", but where would I find them? Fly them in from the southwest at great expense maybe? Actually, I have already found a better gunnite crew that did my last shoot (video not out yet but you can check out their work on our facebook page), but they still probably wouldn't want to do it in thin layers (or would charge me many times more). So, it becomes a compromise between quality and cost. Of course, a minimal quality is needed (and my construction is certainly strong enough to meet that), but I also needed to control cost or I would not have been able to afford to have the crew out at all...
One last bit (you hit a lot of points with your long comment), yes, the plan is to have the insulation on the outside so I can use the thermal mass. In my case, the walls are 6 to 8 inches thick. But my thermal battery also includes a lot of soil before the insulation umbrella, so I will have a much larger thermal battery than the monolithic dome style you describe. Also, rigid insulation panels are considerably cheaper than the sprayed polyurethane foam and I don't need to pay for the expensive dome form, etc. I looked it up and monolithic dome construction (as you describe) was several times more expensive (in terms of the basic structure) then the steel and rebar type construction method that I used. Also, a monolithic dome was the only type of construction completely prohibited by my neighborhood.
What I wrote isn't theoretical. It is used by Monolithic, www.monolithic.org. Cost me $1K to learn it. I shared it for free. I understand your problem with shotcrete crews though. They are in it to make money and the faster they do the work, the more money they make after labor costs, but isn't that true for any contractor, some value the quality of their work as much as the money they make.As far as owing my own shotcrete pump, I do. I got it, a mixer, fits a skid steer, two inflators for the dome, and a 50' air form for $8K. I got it very cheap to new ones.If someone were going to purchase a shotcrete pump from Monolithic, I'd recommend their air motor pump. It uses the same towable compressor you use to shoot the cement. I ran across a guy who replaced the air engine with an electric motor.Part of the pump process requires you to reverse the pump so that if you want to stop for a second, the cement doesn't continue to come out. He designed an electronic circuit that in conjunction with the electric motor allowed him to run the pump and build his dome all by himself. He was able to mix the cement, load the hopper, go inside and start spraying. When he thought the hopper was getting low, you didn't want to run dry as it is harder to prime, he could reverse and then stop the pump. He could then repeat the whole process. That is a lot of work for one person and he is a better man than I'll ever be. LOL
By "theoretical" I didn't mean it couldn't be done. I just couldn't find anyone to do it within a thousand miles of my site. I am aware of the monolithic guys. The monolithic dome crews that do this all the time charge several times the cost of the pool crews that I hired, and I would need to get them and their equipment to travel thousands of miles to my site... In my case, I didn't think it was worth it. I guess I made a similar calculation when I decided to have a mix truck come in instead of mixing my own. It sounds like you got a great deal on the mixer and the form. Did you have to pay for any engineering stamp from the air form company? You couldn't build without one in my area. Good luck on your build. It sounds like it will be even more hands on then mine. If you have your own channel and share videos or updates, you can let us know here and/or on the facebook page. I am sure people who are interested in my project will be interested in yours too.
I did the math and realized that renting a skid steer quickly adds up. I bought that one for what it would cost me to rent for a couple months. It needed a little work, but fortunately, my father is very handy with stuff like that and we were able to make it run nicely for less than 200$. It had paid for itself many times over. So, in my case, since I owned it, the only person I needed to worry about was the 12 year old's mother... His grandmother wasn't too thrilled either.
My father and Uncle had me using backhoes when I was 6, my grandmother had me using 4400 John Deere tractor by age 10. Nothing wrong with him letting the boy learn, you never know when that know how well come in handy.
I'd find another concrete guy needs to time. Looks like the guys did nothing. Troweling is so easy your 12 yr old son could've done a better job than those clowns. 250 for a finisher. Find some laborers and in five minutes they can trowel it smoother than that. You live and learn. Those guys wasted your material. And if the shotcrete was sagging they could've adjusted the mix.
Yes, no video yet, but for the central tower, mezzanine and office apse, we hired a gunnite crew that did a much nicer job. They smoothed things nicely, cleaned up their messes, etc. and they did it for the amount quoted (which was about the same as the shotcrete price).
I really appreciate the detail and clarity you go into with this entire channel, mistakes and hiccups especially. Your honesty about problems and mistakes are one of the most useful parts and makes the channel a great resource. I think your home is a bit of a moonshot, but I'm glad you are documenting it so completely.
Looking good. I must say, your website is much more comprehensive than I expected. You have done a great job researching! I'm very interested in learning more as the house is completed and you continue to share new developments. Thank you for sharing!
I've watched the last few of your videos. Thanks for taking the time to film this. I've never seen a house built this way.
This is one of the most interesting builds I've seen, and it looks like you guys are hard workers, enjoyed watching all of your vids, thanks for taking the time to do this so others can see how much work and time it takes to do something this complicated . Thx again !!!
I've wanted to do the same project and my thought was, shot create and then covered with pond liner not sure the cost deference between pond liner and water proofing but I I would think the pond liner would have the potential for lasting longer... great project and you guys are doing a killer job. 👏👏
Wow I really like what you built. If you like it and the family likes it well that’s all that matters. I’ve been in construction for a while and every one seems to be an expert. It’s amazing who will toss around comments and I bet they never built anything outside the norm. God bless 🙏.
Soundtrack is on point.
The guys who shot that concrete did a terrible job.
i was sayin the same damn thing
I am always looking forward to see your progress.
Me too.
Keep those vids coming. I just started on design elements for my own ESH and hopefully will break ground within the next year or so.
How thick will the layer of earth be on the sides? Just asking because wondering about the solution you have got in mind for the sidewindows, to get daylight in. And How they will hold up the earth above, cause the rooflights make the Impression that the earthlayer will be pretty substantial.
Great project by the way. It makes it clear why everyone is building straigt walls, its just faster/less work and more preprocessed solutions on the market. So respect for the extra effort to make it that special. Curvature on the roof is a different Story, thats totaly perfect in terms of loadbearing. Keep on rocking.
I wonder if you would have went to big box store and bought all their "oops" outdoor latex paint and sprayed it over the waterproofing. It should have stuck well and the heavy pigmentation should block UV very well. It will eventually be covered so the color is not important. I used to do that to the inside of boats when I was rebuilding rotten floors and sterns.
Yea, that sounds like it would have been a great idea. Never occurred to me at the time though ;^)
Latex paint will not hold up when introduced to moisture. Acrylic is better.
Is there any more videos after this one, I'd like to see it finished
There is a whole bunch more footage on my computer waiting to be edited down into something watchable, but we are not quite finished. I just buried 2/3rds of it this week and you see more about that on Facebook (more up to date) facebook.com/HomeintheEarth/ And yes, I would also like to see it finished.
Oh yea, go ahead and subscribe...
I am shocked on what the waterproofing costs! Last week I had to repair an old asphalt roofing as it was leaking and I did so with a kind of liquid tar/rubber material that came in buckets. It cost me about 10 USD for 20kg bucket. This is for waterproofing roofs.. out of the bucket it has the consistency of a thick yelly and can be brushed on or rolled on, after drying it is like a rubber coat. So this is why I am shocked about the pricing you mentioned. I cant compare the quality of the products but seeing it usage and the problems you had with filling in rough concrete and then worries about UV destabilization, i feel the product I am referring to would do a better job for a fraction of the price. If you are interested in details then let me know, I have the empty bucket still around and can send you an image for reference.
ps, only just discovered and subscribed to your channel. Love the work you do and the dedication you show! Keep it up ;)
Yea, sure. I would love to know what it is. My guess is that it is the sort of "damp" proofing that wouldn't work well enough for my application, but I would be happy to find a cheaper solution than the Blue Max.
That coating put on early was actually a good idea if water would have leached into the concrete cracks and froze it would have been a bigger issue later on.
Yes, I hope it did some good... I guess I just wish I could have also put the earth up before winter.
wow great job but WHAT was THE COST?????
I am not very familiar with concrete work but the finish looks very rough. Way to rough in my opinion. What kind of material is this? Is this kind of finish typical for it? The second thing is, I have often seen workers are spraying water on the structure to cause slow drying to prevent cracks and shrinkage. Does this technique not work with your material? Great project by the way! Thumb up left!
Yes, it is very rough. Normally a crew would have a few guys to apply the shotcrete and then a few more to come behind them and cut it smooth. When this job was done, they often came out with only the first 3 guys. Since then, I have not let this crew come back unless they can bring the finishing guys. The material is "shotcrete". It is a 7 sack mix with fly ash and pea stone rated at something like 8900 psi compressive strength. Yes, keeping it wet for a week (or waterproofing it right away) allows concrete to cure better and stronger.
Looking great Simon! In what ways will the blue Maxx be better than tar for the water proofing?
This liquid rubber is actually waterproof... So waterproof that you could even put it on the inside (although outside is much better). It is elastic, so it can stretch to cover any cracks that form. And it is smooth and clean so we can climb on it later.
On the other hand, Tar has not flexibility and will open up along any cracks that form under it (concrete always cracks somewhere). It also doesn't really stop water, under pressure, it just slows it down. Tar is actually classified as "damp proofing". Tar is also dirty and smelly and not something we would want on our job site when we need to climb on the roof so often. It is used so dominantly just because it is cheap and the people who are applying it do not have to live in the house.
For earth sheltered homes, you just can't take that risk.
Good deal. With the UV damage did you end up adding an additional layer before burying the structure? I love following the project but my only fear has always been water getting in.
Sad to say it still isn't buried... Most of the footage in this clip was from nearly a year ago, but those last few video clips were from Monday night. We need that one last round of shotcrete (one day's work) to close off that roof section and finish the dormer eyebrows before we can bury it, and we just have not been able to get a crew out this year. Just not enough of them around and doing pools is easier money.
When we are ready to bury, I will re-assess the damage and decide what to do. I am concerned that simply adding another layer won't work because it will stick to the UV damaged surface and not properly bond to the rubber or concrete below. Sort of like painting over rust. Maybe if I power wash it first...? Anyway, I am sure we'll figure it out.
Just ask the companie on ther opinion.
How long does the "Blue Max" last after burial ?
I think it should be pretty permanent once buried. UV is its weakness.
I'd probably have put a pond liner over it and used that rubber stuff only for the ceiling lights. Connect the pond liner (epdm) to the rubber stuff with some hardcore glue like Innotec (even dries under water)...
That pond liner stuff made from epdm is extremely durable and you don't have to worry about all cracks nstuff, only about whereever you have stuff going through it...
Or use some bitumen coating/mats... but that rubber stuff.. no. I don't think that was a good option given your situation where time is a problem.
Yup, I also have a pond liner (my excavator gave me) and a bunch of used billboard vinyls (17 mil reinforced)... I'll be using all of those and more to make sure this all stays dry. This blue max is just the first layer.
6 - 12 year-olds are educational sponges. If they show an interest, give them the reins.
How much was this building?
Just for shyts and giggles,,,,how much do you think you have tied up in this build ?
It was budgeted at something in the seventy something dollars per square ft range. I think it might end up closer to ninety by the time we are done (some things, especially shotcrete, went over budget). The garage was 28$/sqft with the bathroom and electrical and waterproofing
After your are ready to cover spray a light coat over previously covered affected by UV along with new areas
Yes, that is my most likely solution. I will be needing to waterproof the new areas anyway, so it will be minimal extra work to just re-hit the worst affected areas while we are at it.
What was total cost for all to be done
The garage from, footing to waterproofing, including end walls, garage doors, electrical, plumbing, etc., came to ~28$/sqft.
Im wondering about repairs
Yup, it can be a challenge if the problem is now under 10 ft of dirt. But there are plans for everything. Ask about a more specific repair and I will try to give a more specific comment.
When do you fill it all in?
I plan to take care of the first 2/3rds of the burial this September...
Liked & Subscribed
great job but i think you should have looked into buying the 55 Gallon Drum Regular Grade $1,772.21
We considered it, but moving those around, getting the waterproofing out, etc. seemed too inconvenient for the savings. We are not on the industrial enough scale for that.
cool I was Shure you thought about it but never hurts to ask
Yea, they also sell those even larger 275 gallon totes for an even better price per gallon, and it has a tap so you could get it out into a smaller bucket easily, but that is just much more of this stuff than we thought we needed at the time.
since you have to recoat have you thought of contacting them and seeing about working out a promo video for a discount with your project I would think they would be interested in more exposure
Could he have just wrapped a damp proof membrane over it before burial? Would that be more expensive
I will also do that. Water proofing is so important that more than one layer is really a good idea.
I really enjoy ur narration. You sound cute.
Nice choice of back track haha.
We were humming it the whole time we were up there working, so there really wasn't any other choice ;^)
thanks for video guys ill be using an epoxy or poly basically bed liner from this company linerxtreeme very good product and not a water somethings are just not best made with h20
Just because something is water based initially, doesn't mean it is soluble in water after the chemistry does its thing. But yea, there are lots of great coatings out there. You just need to balance a bunch of competing parameters and choose what works for you.
Uhm, ya’ll know you should paint over Blue Max as soon as possible, right?
Don’t wait for the dirt to protect it.
Every project has delays, so break the work into stages you can complete quickly.
This is awesome
If your shptcrete is shot properly by pros it shouldnt sag especialy when it isnt over 6 inch thick .after 6 inchs u have to consider another layer cage of rebar
You can't rely on weathermen, because they rely on computers!
cool 😎👍🏼
shotcrete was the wrong way to go, aircrete with a kappa applicator would have saved you a heap O dough , I could see using shotcrete on the inside but even that I would have used a 25 lb spray scoop not tryin to be critical but your finishers were horrible
Looked up the engineering properties of aircrete and it is not nearly strong enough for my application. Like hemp crete or other non-standard "cretes", it has lots of fans, but is not the "way to go" for anyone relying on it to hold back serious earth loads. I had planned to use it to fill the the spaces between my shotcrete vaults (fill the space with insulating concrete that doesn't add a lot of weight), but there was no one really doing it in my area willing to bid on the job (there was one terrible company using it to repair flat roof commercial buildings). I also looked into buying my own equipment, but eventually (for a number of practical reasons) decided it was not the "way to go".
Pick a different back sound track, the current one sucks.
No offense, but who ever did your shotcrete did a poor job. I watched previous videos, and they basically flowed it in. If, instead, they had applied the shotcrete in 1/2 inch layers, allowing them to set, not cure, but set, between each layer, you would have had the same strength without the waste and gapping around openings. Trowelling after shooting, will actually cause the shotcrete to flow or sag when sprayed on that thick. This will not affect the cured strength of the concrete.Depending upon the area sprayed, they could have done a layer in the morning with a second layer in the afternoon, repeating the process until you've reached the desired thickness. Because of this, unless it is a large build, you cannot use a ready mix delivered and must use a batch mix, mixed on site.Correctly applied shotcrete will be applied as if you are spraying a heavy paint, too much and it runs (fallout), too little and you don't get even coverage. If you're worried about X-raying with the rebar showing through the finished concrete, simply use a grass whip to scrape the exterior rebar between sprayings. To prevent slumping at the base, put two rebar around the base of the vertical rebar and fill it first, scraping the base rings with a grass whip.You will need to use certain plasticizers to get a slump without the water content. Basically a plasticizer is a type of soap that allows the slump, without the excess water. To test if you have the correct slump, take a hoe scraper, looks like a straight hoe, scoop up some cement and with the face held horizontal, tap it several times till you reach the thickness you are spraying. You should then be able to turn the hoe scraper face vertical and the cement should remain on the face. I am very interested in doing what you've done. I'd like to do it from the inside, spraying it first with 3 inches of 2 lb. closed cell polyurethane foam, then hanging the rebar and spraying shotcrete on the inside. With concrete on the inside you get a thermal battery that once warmed or cooled, as the season directs, you will have about a 70% to 80% energy savings. Hope this helps other who may want to try your build.
There is the theoretical and there is what you can actually get done. I appreciate your comment to help anyone else planning to do likewise, this is why I film and comment so openly about my own journey. Here are some of my "realities" related to your comments. 1) Shotcrete crews prefer easier jobs to difficult ones. The crew was simply not willing to drag a heavy hose back and forth to do thin layers, I could barely get them to move it if they were overloading one half of an arch. Maybe that means I should have hired a different crew, but keep in mind that I couldn't even get another crew to come and give me a quote. There is too much work and it is too easy for the crews to turn down a "difficult" GC and take an easier job (such as a pool). If you want to get it done, some times you need to compromise a little. My original plans did call for most of what you are describing. I wanted things shot from the inside and finished nicely. No crew (including the one I did hire) would take on that work. Gunite crews will mix on site, but I don't know of any shotcrete crews that would do that when it is so much easier to just order a mix delivered. 2) They come with their own methods. I also knew lots of things about how shotcrete "should" be applied. If you find a crew that is willing to do it your way instead of their own way, I would be very surprised. Most of the time, you can expect to tell them what to do, but it is considerably more difficult if you try to tell them how to do it. If you try that before they on site, you may find they just take an easier job and never show up. You may find that you will need to do it yourself if you want it done a very specific way.
Several people have suggested I should get a crew experienced in "monolithic dome building", but where would I find them? Fly them in from the southwest at great expense maybe? Actually, I have already found a better gunnite crew that did my last shoot (video not out yet but you can check out their work on our facebook page), but they still probably wouldn't want to do it in thin layers (or would charge me many times more). So, it becomes a compromise between quality and cost. Of course, a minimal quality is needed (and my construction is certainly strong enough to meet that), but I also needed to control cost or I would not have been able to afford to have the crew out at all...
One last bit (you hit a lot of points with your long comment), yes, the plan is to have the insulation on the outside so I can use the thermal mass. In my case, the walls are 6 to 8 inches thick. But my thermal battery also includes a lot of soil before the insulation umbrella, so I will have a much larger thermal battery than the monolithic dome style you describe. Also, rigid insulation panels are considerably cheaper than the sprayed polyurethane foam and I don't need to pay for the expensive dome form, etc. I looked it up and monolithic dome construction (as you describe) was several times more expensive (in terms of the basic structure) then the steel and rebar type construction method that I used. Also, a monolithic dome was the only type of construction completely prohibited by my neighborhood.
What I wrote isn't theoretical. It is used by Monolithic, www.monolithic.org. Cost me $1K to learn it. I shared it for free. I understand your problem with shotcrete crews though. They are in it to make money and the faster they do the work, the more money they make after labor costs, but isn't that true for any contractor, some value the quality of their work as much as the money they make.As far as owing my own shotcrete pump, I do. I got it, a mixer, fits a skid steer, two inflators for the dome, and a 50' air form for $8K. I got it very cheap to new ones.If someone were going to purchase a shotcrete pump from Monolithic, I'd recommend their air motor pump. It uses the same towable compressor you use to shoot the cement. I ran across a guy who replaced the air engine with an electric motor.Part of the pump process requires you to reverse the pump so that if you want to stop for a second, the cement doesn't continue to come out. He designed an electronic circuit that in conjunction with the electric motor allowed him to run the pump and build his dome all by himself. He was able to mix the cement, load the hopper, go inside and start spraying. When he thought the hopper was getting low, you didn't want to run dry as it is harder to prime, he could reverse and then stop the pump. He could then repeat the whole process. That is a lot of work for one person and he is a better man than I'll ever be. LOL
By "theoretical" I didn't mean it couldn't be done. I just couldn't find anyone to do it within a thousand miles of my site. I am aware of the monolithic guys. The monolithic dome crews that do this all the time charge several times the cost of the pool crews that I hired, and I would need to get them and their equipment to travel thousands of miles to my site... In my case, I didn't think it was worth it. I guess I made a similar calculation when I decided to have a mix truck come in instead of mixing my own. It sounds like you got a great deal on the mixer and the form. Did you have to pay for any engineering stamp from the air form company? You couldn't build without one in my area. Good luck on your build. It sounds like it will be even more hands on then mine. If you have your own channel and share videos or updates, you can let us know here and/or on the facebook page. I am sure people who are interested in my project will be interested in yours too.
rough concrete work a better job would have saved time and money later
I totally agree and tried to convince the shotcrete guys, but they were pretty stubborn about it.
hopefully whoever you're renting from doesn't know that you let your 12 year old drive it!
I did the math and realized that renting a skid steer quickly adds up. I bought that one for what it would cost me to rent for a couple months. It needed a little work, but fortunately, my father is very handy with stuff like that and we were able to make it run nicely for less than 200$. It had paid for itself many times over. So, in my case, since I owned it, the only person I needed to worry about was the 12 year old's mother... His grandmother wasn't too thrilled either.
You did well. Supervised him and gave him a skill he can use all his life. YOU ARE A GREAT DAD!!!
My father and Uncle had me using backhoes when I was 6, my grandmother had me using 4400 John Deere tractor by age 10. Nothing wrong with him letting the boy learn, you never know when that know how well come in handy.
I'd find another concrete guy needs to time. Looks like the guys did nothing. Troweling is so easy your 12 yr old son could've done a better job than those clowns. 250 for a finisher. Find some laborers and in five minutes they can trowel it smoother than that. You live and learn. Those guys wasted your material. And if the shotcrete was sagging they could've adjusted the mix.
Yes, no video yet, but for the central tower, mezzanine and office apse, we hired a gunnite crew that did a much nicer job. They smoothed things nicely, cleaned up their messes, etc. and they did it for the amount quoted (which was about the same as the shotcrete price).
How much was thT build?
By the time we moved in (after kitchen, windows, tile, paint, HVAC, etc.) we were at about $92 per sqft.