Pouring a DRY vs WET Concrete Slab /// Cutting Them Open AFTER 90 days!! ///Home RENO Ep. 6
HTML-код
- Опубликовано: 1 май 2024
- There has been a lot of talk on Social Media about doing a DRY Pour concrete slab and it being just as strong as a Wet pour concrete slab. In this video we put both of them to the test and cut open some sample pieces to revel its curing cycle. If you have done a dry pour before please share your results with everyone in the comments!
WET vs DRY STRENGTH TEST VIDEO: • The TRUTH About Dry Po...
Make sure to Subscribe and Hit the Bell notification to follow along on our journey with this Renovation!
Get your Komar Gear Here teespring.com/stores/komar-pr...
Check out my Recommendations for Beginner Tools www.komarproject.com/ndiytools
FOLLOW ALONG ON SOCIAL MEDIA:
LINK TREE
linktr.ee/KomarProject
TOOLS USED IN THIS VIDEO:
Concrete Float amzn.to/3SeaDzq
Edge Float amzn.to/3OlGtcw
My Grinder amzn.to/3OpxVkB
Masonry Blade amzn.to/3SEM3sN
Reciprocating saw amzn.to/49es7mb
Rebar amzn.to/4biGEPy
Bailing Wire amzn.to/42k77rK
My Favorite Drill Set amzn.to/42idzjf
3” Screws amzn.to/3HFAonh
Miter Saw amzn.to/4818ooZ
Dream Home Renovation Episode 1 - • I Started a Massive Re...
Dream Home Renovation Episode 2 - • My Wife made me Rip Ou...
Pre-Construction House Tour Video: • We Just Spent Our LIFE...
OTHER VIDEOS TO WATCH
Modern Dog House • How to Build the Perfe...
3 in 1 Grill and Pig Roaster • You WON'T Believe What...
Mini Split Installation • How to Install a DIY M...
Miter Saw Zero Clearance • Zero clearance insert ...
Ultimate Chicken Coop • How to Build the ULTIM...
10,000 Pencil Table • Epoxy Coffee Table out...
Wood Lowrider Bike • Making a ALL Wood Low ...
Router Table • Ultimate Router Table ...
Concealment Flag • Motorized Concealment ...
Backsplash Tile Installation • How to Install a Subwa...
Music By: www.epidemicsound.com/sfx/
#concrete #drypour #Concreteslab
DISCLAIMER: Links included in this description might be affiliate links. If you purchase a product or service with the links that I provide I may receive a small commission. There is no additional charge to you or anything different you have to do. Just shop as normal.! Thank you for supporting me so I can keep creating awesome content for you. 
Хобби
![DRAGON BALL: Sparking! ZERO - Master and Apprentice Trailer [BUDOKAI TENKAICHI Series]](http://i.ytimg.com/vi/wNf7A4rHczc/mqdefault.jpg)
I have never done a dry pour. After watching this, I still won't. Thanks for this great video ❤🇦🇺
That's what I was thinking
I did one for my shed. Came out great. It’s been over a year and no problem. I also added cement to the top inch or so of the dry pour so the top would be smoother.
Dittto...!
same. definitive.
im sure some scientist though could make a dry pour mix,
I dont think there would need to be as many rocks in a dry pour.
Still not enough evidence really need to know how different ones work. i hear some just don't work.........
Over 30 years ago, my wife and I bought a new house and fenced the back yard with 4x4 treated fence posts and Cedar slats. I started out setting the posts with wet pour using bagged cement like you did. I got tired of mixing the cement about 1/2 way through the project and started just dumping the same amount of dry cement into the hole around the post. I tamped it enough to hold the post in place then ran a random amount of water into the dry mix. About 25 years later some of the fence posts started rotting out. I dug the dirt away from the concrete holding the posts in the ground and started chipping at the concrete with a heavy demolition bar. The dry pour cement broke after 2 or 3 hits with the pointed end of the bar. The wet pour cement wouldn't break. I had to dig them out. Dry pour made the replacement of the 4x4 posts a lot easier. So I guess the moral of the story... Pick your job carefully for Dry or Wet pours.
I use fast setting Quikrete poured dry and adding water to the hole. Works perfectly. Hey, if you got 25 years I'd say it held up pretty darn well!
Great example. I just said basically the same thing using my mailbox post as an example. Dry pour was the way to go in your case.
instead of posts, you can either use a 6" or a 4" PVC pipe, and fill out with concrete inside, will last way longer, no need to paint, only thing is, to connect anything, will need a concrete bit and anchor bolts.
@@descendingsouls The PVC might be weakened or destroyed by the sun.
I think the PVC is mostly just acting as a form for the concrete.@@ATruckCampbell
I'm a service plumber of 25 years. I must say you did a good job of being descriptive in this video, and you are very informative.
As soon as you hit the dry pour with the hammer I knew it was bad. As a restoration mason, I get paid to hang off tall buildings to fix stonework, and also flatwork like parking garages. An engineer can see a hole and say "fix that"... but the way we masons know what to fix is pinging with a hammer. Bad concrete doesn't make the hammer ring like good solid concrete. Also, the chipping during your cut was a sign that the slab was compromised. Water infiltration will turn a bad slab into a pockmarked field with the freeze/thaw process. Great video, man, really enjoyed it.
So you know, buildings that have withstood the test of time over 1000 years old are buildings being built with dry pour….still up and standing today
Fuck all of that. You couldn't pay me enough
This is the best dry vs wet pour comparison I've seen. I wont be dry pouring!
This is pretty much what I suspected after watching
these dry pour videos for the past couple of years
The dry pour will be much easier to remove . LoL 😂
Perhaps the manufacturer put directions on the package for a reason
pay attention, two different kinds of application, one if dry motar and the other is pre mixed Rock Concrete. How is this even remotely the best Vs?????? You can't compare moter to rock concrete. That's how I can tell you know nothing what your talking about. smfh. if you was a home owner, you would robbed. smfh
@@virgilwalker683 he used the same concrete mix for both you idiot. Same bags.
The sound test says it all.
to someone who is experience.@@TheRawdawg
I have done a lot of bag concrete work lately and after contacting the bag concrete company technical support (both Sakrete and Quikrete), both said to follow the bag instructions. Both said to limit the water to the amount stated on the bag, more water will result in weaker concrete due to trapped molecular water causing voids in the cement matrix when it does finally leave the slab during curing. I mixed 50lb bags to 1/2 gallon of water exactly, and 2/3 gallon for 80lb bags. the consistency was like barely wet dirt and gravel. Your wet mix was extra soupy. When I mixed extra soupy I was using about 50% more water than recommended, and then I added more dry concrete to get to the recommended consistency. This stuff was so dry I was confused how it could possibly be correct. I shoveled it into my forms and it just piled up and up, then I vibrated the mix in place and it collapsed into the forms and water started coming out the top and sides of the forms. It really was the right amount of water. ... I think your wet pour was too wet, but it was better than the dry pour that was too dry. Your sample pad was very much too dry and did not cure, there was not enough water to activate all of the cement reaction. You should mist more water for more times. Your eight, 50lb bags, needed 4-5 gallons of water. Do you think you misted 4-5 gal of water? Your wet mix probably had 8-10 gallons of total water and some of that went into the ground faster than it evaporated up and out of the top. It at least had a chance to activate and cure even if it does have more microscopic holes in the matrix where the extra water was trapped until it finally molecularly worked its way out 90 days later, the dry mix test slab never actually cured. You might be able to finish curing the dry test slab by continually keeping it wet and maybe you could submerge your sample slab in a bucket of water for a few days to see if it will fully cure 90 additional days later Thanks for your presentation, and get and use a mask around dry dusty cement. Silicosis is in your future otherwise. Be safe!
@johnrussell6620 Great response. Saying all the things I was thinking to say as well, and then some! Nicely done.
Great comment that makes perfect sense.
I've only ever done a single concrete pour in my life for a pad like this and my experience was similar to yours with being just barely wet.
I was sure I was doing it wrong because it didn't pour, or look at like so many videos I've seen.
So far so good.
I LOVE reading the comments. Herculaneum came to mind as I thought of him breathing in that concrete dust. Working concrete is a science & an art. Go men! Thank you!
Except every concrete truck pour ever. the difference between 25 gigapascals and 35 gigapascals isn't going to affect a diy project, or any single-family home project.
Thank you Mr. Nye
I did a dry pour 5 x 5 slab 2 years ago because as as a 70 year old lady I couldn’t handle the wet pour method. It’s been fine..I don’t drive anything heavier than a golf cart on it. I intend to do a larger patio area this spring using same method. Best and cheapest way for me to go. No complaints at all. If you have a mixer and preferably some more muscle wet pour might be better but not an option.
Plus, you're not doing anything 'structural'.
70?! respect!
@@jasonenna3544 Well it’s spring and I haven’t started the patio yet. My mother was still gardening and running a vegetable stand at 95 so 70s would be young to her..she passed away at 97. Wish me luck with patio! Unless you were being sarcastic…
@@lorihamlin3604 I was not being sarcastic! im 50 and arthritis is killing me.its awesome you took that on at your age and I love ladies doing such things at any age. I think it is wonderful, take care and good luck
@@lorihamlin3604 I agree, 70 and building a patio is awesome!
This video was very interesting, thank you. Also please everyone, wear a mask if you are dry cutting concrete. In recent years concrete dust has been linked to respiratory problems like Silicosis. Great to see this comparison, many thanks.
And the fibreglass rods. That stuff doesn't do wonders in your lungs
I couldn't believe it when he cut into the test slabs and it was a thick cloud of silicosis straight into his face. Man he really needs to take irreversible lung damage more seriously.
And when pouring the mix.
Who knows what is added in the blending process.
I don’t wear masks.
-Donald Trump
@@karabinas- any reasonable, self thinking American. Oh wait……. Thats just for the flu. Leave it to a libtard to make this political
Love the kind thought of using safety glasses to protect your hat, not enough people consider the safety hazards that their hats face. Bravo!
I would compare it to using a rubber band for a condom to protect a dick.
My only comment on safety, is to wear a mask wnt cutting!!! If you get that dust in your lungs, it's not going anywhere! Your body can not absorb it. There will be silica in the dust and that can cause silicosis. Wear a mask! It's safer!
just like how we did it at the precast...whats life without black snot and getting something in your eye every day?
thanks construction Karen! and gloves and steel toed boots and plenty of water 😆
@@dorse72 You're welcome phony macho man! That dry cough is sounding pretty bad.
This confirmed every suspicion of dry pour.
There was a surprise though in how well it camouflages itself to look like a monolithic slab.
Thanks for sharing. Cool channel
If it's mixed properly it works just as well as the wet method. Treat it like any concrete pad. Mix the water properly with the dry mix and you will be fine. This i know, is true because i did use the "dry" method, however i mixed the water properly with the poor and it was fine.
@@Openrealityif you mix it that’s a wet pour
@@Openreality What is the point of using dry pour concrete if you mix it with water?
Lift that rebar boy! 💪🏻 Easiest way is to put a layer concrete then toss the rebar on top and put another layer.
This has been one of the best wet pour dry pour comparison that I have seen with concrete. Great job showing this to us.
Almost all my uses for concrete are dry pour. One wet pour example was when I poured a pad for a very heavy garden statue. Wet was the way to go for stability and strength. My best dry pour example was for my mailbox post. I dry poured around the post to set it and make it stable. As expected, sun got to the wooden post and cracked it. Also, the wood twisted and bent over time. After 10 years, it was time to replace it. The dry pour concrete around the base kept the post quite stable all those years but was also quite easy to break apart with a mattock and shovel. It made the thing very easy to remove so I could set a new metal post in the ground. Had it been an unnecessary wet pour, the base of the old post would have created a great deal of extra work trying to remove it. Dry pour serves me well in such conditions.
had you used a metal post, your mailbox wouldnt need to be replaced every decade. that also doesnt include other factors like if something was to hit your mailbox, the dry pour wouldnt hold up, and youd have to start over again. same with fencing, sure the wood looks great, but if you use a metal post as a base and build off of that, you wont ever really have to worry about replacing the whole fence, just the wood. also with a wet pour, since it doesnt fall apart so easily, you can simply dig around the footing a bit, rock the post loose, and pull the entire post/footing in one go, not that youd really need to since it would last much longer than a wood post/dry pour combo.
@@thaboss32 That's a valid point. I didn't have metal and, at the time, the wood was plentiful and cheap. All I lost was a little labor for the next 10 years of use. I then replaced it with a metal post. The dry fill I had used around the wood was an advantage since it was much easier to remove yet it had served the purpose for a decade. You're right, of course, metal would have lasted longer in which case, a wet pour would have been the proper base. There was a wet pour base used for our metal fence. I've seen such fencing last a lifetime, thus proving your point.
Mr. Komar, this was by far the most instructional dry vs wet pour. I have watched so many but the hammer test made it perfecty clear. The sound difference made me nervous! Wow! If this doesnt convince anyone i don't know what will. With all the babysitting of the dry pour, to me, it seems easier to do a wet pour anyway. One and done.thank you!
Wet pour, you control the moisture content and can give the cement exactly the right amount of water to make sure it hardens fully without leaving too much water, which causes pores in the concrete which weaken it.
That question was on my mind for a long time, just never found the time and the right project for it, you saved me time money and aggravation!! Thank you very much!!
Always been Leary About dry pours after decades of concrete work, now I can see why. Great demonstration!
You're the only person I've ever seen on the internet that knows the word LEARY and also doesn't replace it with WEARY (instead of wary)
As a now retired heatpump installer and serviceman(in trade 45+ years), i feel i should mention, how many systems i have seen, that had rusted out bases of the outdoor units.
Almost all of them were directly fixed to a flat base - usually a concrete pad.
We always installed on top of 4x4 treated timber or hard wood blocks(fixed to base).
The reason being, when fixed direct, leaves and debris build up under unit, and stays damp most of the year, whereas raising unit above pad on wood blocks, gives a lot more clearance for rubbish to dry out, and makes keeping underneath clean easy.
I do not see any drains fitted either, do your systems not come with a drain fitting, and rubber bungs for the drain holes in it?
Direct fixed and draining water onto concrete pad, is imo and personal experience, likely to cause unit to rust out its base within 5-10 years.
Thank you. Great comment.
Yeah. This dude is sloppy. I have no idea why someone would claim to be a pro and do such amateur work.
I’ve got 2 ac units both on concrete and they have no rust issues. Both pads are elevated the thickness of the pad off the ground. I also keep them clean and clear so it could be the environment and the user that makes a difference.
@FishFind3000 I found @retiredkiwi's post extremely accurate and helpful. He was sharing experience from a lifetime of working. Logically, what he said makes sense. Could it be the user? Perhaps...less logical to think metal is rusting more from a user error than from conditions and matter exist simultaneously in the same place. It is logical to see how buildup of organic matter directly against metal could cause serious oxidation issues. Although nothing is always, as there are exceptions to most things.so it is possible that the directed attack at valuable information with a slight like somehow the OP is using the ac in a manner that could cause the exterior metal components to prematurely oxidize.
I agree to this the alkaline and calcium inside the cement "Portland" it will react with other metals and allow for rust to build up. Usually this is where the painted surface though is damaged, which can easily occur. So yes proper drainage and or a plastic drain pan, or even PT wood, something in-between the unit and the concrete will help provide more protection to slow down any possible rusting to occur.
Wow, saved by the video. I was almost talked into doing a dry pour for my new steps. I'm glad I found this on You Tube before I took his word!
How do you almost get talked into doing something this retarded? Lmao humanity is doomed, if you didn't know that it's objectively better to mix everything first before using it.
if you already know how cement/concrete works on a chemical level, you already know the answer to this question.
basically, what makes concrete strong are the CSH gel produced when cement reacts with water. So with a dry pour, you're only basically relying on the moisture of the air to react with the cement so only the surface actually becomes "concrete" and the inside is just a mixture of sand and cement.
Thanks for this. I've done dry and wet pour for fence posts . The wet always held up longer. Now You gave me proof! Thanks again.
From what I've seen with multiple experiments is that wet pour concrete almost always exceeds 4000 psi (usually 4000-4200 psi depending on curing temperatures and water, etc.). Dry pour tends to have a higher variation and be about 60-85% strength, about 2600 to 3500 psi. I believe with dry pouring there is more trapped air in the pad and less interlocking at the microscopic level.
Hydrated Cement (calcium-silica-hydrate) creates long chains of silica tetrahedra (4 armed molecules that form very craggily chains) surrounded by and holding onto pockets/layers of calcium oxide (quicklime). In normal concrete the length of these chains is limited mostly by time and adjacency of open ends as initial curing kicks off. I think by dry pouring concrete the silica tetrahedra chains are probably significantly shorter and tighter...there is less tangling around the calcium oxide. This probably makes it generally crumblier.
Now 2000-3000 psi is fine for non-structural use, and I think it greatly depends on how well its watered (sealers/coating tend to be good to help with surfaces). I've seen people be very successful laying the dry powder in 1" layers and misting as they go, and then after 18-24 hours start soaking the slab as much as possible. But it can definitely take 6-9 months to reach its optimal strength. I don't know if curing additives and superplacticizers change this impact, or how things change with using high-strength concrete mix.
I figured there was something chemically different happening. I'm not a materials scientist, but to borrow a metaphor from cooking, it's probably not unlike the gluten in bread flour. If you just pour the water directly on top of the dry mixture of a bread flour without actually kneading it and expect it to make bread, you're in for a bad time.
@@katarh Your analogy is dead on. Long carbohydrate chains in gluten is extremely similar to what is probably going on here.
I'm presuming this guy is a professional but for anyone who isn't used to using an angle-grinder, keep the guard on and keep your body to one side of it!
Interesting video👍
For sure, face shield, as well, if available.
@@aculpoca Indeed.👍. Ear defenders & a mask too.
Chased many a wall & cut many kerbs/lintels, the dusk is no joke.
Yeah, I reflexively winced when he started cutting without that guard. Good video though!
@@JustinMurray170fin Yes Silicosis is no joke.
Pro or not, this guy has no regard for his own safety. Use your own judgement and don't follow him just because you see him on youtube.
I've seen a video a while back that had me thinking that I might try a dry pour on some concrete work I need to do this summer. After watching this video, I've just changed my mind. Wet pour only! Thank you for this video.
I've been in a few arguements with folks on RUclips who insist there's no difference between wet- & dry-pour results...
Thank You for this video! i'll be sending this link to every future RUclips "Expert" who needs to be taught a valuable lesson.
If he had done the dry pour correctly... You cant wait overnight to saturate it like he did after misting it. No, a dry pour isn't "better", but is sufficient in some applications. This video is misleading as he misted it, then let it sit overnight before saturating it. This will lead to a brittle surface and edges and unbalanced curing.
Did dry pour for fence posts when I was a kid ( 15 years old)and had to rebuild my girlfriend’s mom fence. Had to replace every post after 6-8 months. Did it the right way the next time and it’s still standing 20 years later.
My cousin made himself a walk way and he just dumped dry concrete in the form and in about two years he was walking on gravel with gravel growing up through it. As a concrete finisher. Not only do I care about the look of the finished product but the strength of it. I have poured sidewalks , driveways, and basements or garage floors that 20 years later still have not cracked and looks great today. I also did HVAC work for many years and my boss would pour a pad and he would just screed it level and let it sit up. I started finishing the pads and using an edger and he really liked the way I was doing it the results of finished concrete looks so much better than someone just half way doing the job.
idk how the idea of a dry pour even comes into someones head. do they not know how concrete works? absolutely moronic.
And I think finished concrete lasts longer
@@davidanderson9845 Troweling will remove some of the air from the concrete and concrete is stronger than air. That is why the dry pour is weaker, the cement can not form a paste with the water and push out the air when its worked.
Looking forward to the follow up video where you pour a slab using only concrete extracted from your respiratory system.
Ouch...
yea I don't think he believes in silica
And then the trolls enter the room with their stupid remarks.
yeah, this shot ruclips.net/video/3D11YX_DhZA/видео.htmlsi=lPKQ_hZNK611ZCTT&t=795 is shameful. fancy not using basic ppe in 2023.
@@elguapo5467 The comment had a trollish tone, but it's a serious issue. COPD does not care if you're a professional or an amateur - you get that stuff in your lungs over enough years, and it WILL make you sick. There's a reason they sold the high end PPE in hardware stores long before the pandemic hit.
I have been waiting for this to be done by someone. I test concrete for a living and I knew there was no way in gods great earth that dry cure could work. Too many concrete samples taken in my life. Thanks for the information and it was a good head to head test.
I knew it. Just haven't found a video where a proper test was done. 👍
I've always had my suspicions that dry pour was not the way to go and this video confirms them. Wet pour all day long. Thanks for sharing!
Case closed!!!
Yeah it’s one of these silly ideas propagated on RUclips. Ever bag of concrete ever says to mix water-except post holes where strength doesn’t matter much.
Doing dry cement is recommended for fence posts or other in ground none load bearing applications. It works well enough for that . Don't know why people try to do it for other things.
What a load of nonsense
@@lucaschapman1966 to what?
Great and informative video. I was a contractor for a long time and never thought of a dry poured slab. There are many people out here that don’t know anything and are here to learn. Some of them will hang on to your every word and actions. Reconsider showing people how to use that grinder without a handle, with an oversized blade and guard less. I have seen some bad things happen with that setup. I also wish someone told me to wear a mask when I was younger,I just didn’t know. Keep up the good work
Very good demonstration mate. You did an excellent job in the production of this video. Thank you for sharing your experience and knowledge with me.🌞
I like your willingness to experiment. My daughter’s a lung doctor, “Do you work where there’s any kind of dust produced by power saws or grinders?” is one of her standard questions she asks her patients. It’s a long list.
Did you track the amount of water you used on the dry pour, do you think that the lack of strength has anything to do with not enough of a key ingredient, water, that is needed for the chemical reaction in the curing process?
I'm expanding my front porch. When this house was built, the builder decided a front porch running across the enter 69' front of the home was sufficient being just 3'6" deep. So, wifey, the "construction expert" has been telling me I should "just do one of those dry pour slabs". Since I'm also expanding the roof to cover the 4' expansion of the porch slab, there will be a fair amount of weight resting on six columns. Just like I would never use bell wire to try to power an electric oven, I will never use a dry pour slab for any serious slab project. Yes, mixing two or three bags at a time in the portable mixer is a lot of work, but so is replacing a failed roof due to a failed slab.
I've used a harbor freight mixer (the larger one) for a few slabs around the house. I find two 60 lb bags at a time is good - not too much for the mixer or me wheel barrowing it. I have the wife help me on the bigger pours (20+ bags), she fills a bucket with the water for two bags (measured out beforehand and marked on the bucket) while I spread the last batch of concrete. 5x10 is about as big as I care to do in one pour. Can do a larger pad in cooler weather - don't want the beginning of the slab setting up before you pour the last of it.
I have a "construction expert" also. Actually an "everything expert" I have no idea how I get anywhere I need to go when she is not with me or get any project completed when she is not around.
@@benjaminreinhardt259 Yeh, that's probably my limit - two bags at a time, although I was using the 80 lb ones. Hurt for a week... we have two more sections to do - about five yards.. this time, we're having the ready mix company bring it over.. and after checking the calculations on price... i'll be saving about $3-400 bux by using them as opposed to getting bagged crete from our local supplier... we're about 30 miles out of the big city, so prices here are a bit higher than at the "in town" big box stores.
@@usapatriot1234 I love the comedian who says that about his wife when she's with him when he is driving... "funny, but I have NEVER asked "why did i park there?"".....
I've always been curious about dry pours. After watching this, wet pour is the clear winner.
Great video, I've wondered about "dry pour" before and I've seen people do it for fence post but never liked the idea. I'm glad I did it the old fashioned way for my home DIY projects
Thank you for sharing this with us. Everyone stay safe, warm, happy and healthy. From Henrico County Virginia
The dry pour videos I first saw made it abundantly clear that this was a quick fix for foot traffic only. They would never use it on a driveway. They used it onder a chicken shed and as a small slab out the back door. Context of purpose is everything here. Imagine if you are older or disabled and just want to get rid of that muddy path from garage to house. Mixing and pouring wet cement may be too much for them. Also the original was done in an area where the ground is usually damp. I would not try this in the desert. But like he states, it is working fine for his air conditioner.
I'm using the dry pour method to create a 2.5-inch surface on top of a six-mill plastic vapor barrier for the crawl space under my house. For that application, I'm not having any issues. Note that I'm not beating the dry pour with a hammer.
Yeah, dry pour seems like a good quick and dirty method for a non structural type of thing that only has to last a few decades at most. Other examples in the comments have been for fence posts or mailboxes; pathways and anything that won't need a bolt through it are probably all fine too. But for anything that you want to last 50 years, that has to support the weight of a building, or that has to have stuff anchored to it, the wet pour is probably the better option.
@katarh I agree with you, but let's take your observation one step further regarding an important project: I would never use the wet-pour method relying on concrete from a bag; I would always use the services of a concrete contractor who pours concrete from a truck and uses concrete from a commercial plant.
Thank you very much for this video. Also thanks for the comments that explain drypour is great for holding wooden posts in the ground that will likely rot in 10 years and need replaced and the dry pour is easy to chip out and dig up to redo
Great video!
After 30 years in the trades doing concrete, etc. It's nice to see a real Pro using sound to assess the quality. So many scrubs out there giving clueless advice.
Do it correctly the first time or do it twice. Measure twice, cut once.
Measure twice, correctly, cut once, correctly.
I have guys here who swear by dry pouring. It never set well (pun intended) with me, but I couldn't put my finger on why. Thank you so much for doing this experiment. This is fantastic information.
It doesn't make much sense to me, its nearly as much work as a wet pour I guess people want to feel special and brag about doing it differently 🤣
@@whitexeno TBH i would say a dry pour is even more work, you have to water it xx times with xx minutes between,
but on wet pour you mix it, make it smooth and then wait for it.
@@anderssrensen7533except you don't need to carry heavy wet cement, mix it, shovel it in, and clean all your tools before it hardens and you're only watering every so often
@@scottbitz5222 well the strengt of dry pour really scare me, it looks really really weak compared.
if you carry 20 kg dry or 20 wet cement its the same weight :p and he said wet and dry took same amount cement, also the dry pour need a heavy babysitting cause of watering xx minute xx times
But the wet pour your not just carrying the weight of the concrete, you're also carrying the weight of the water. Still, not an excuse not to wet pour. I think there is a way dry pouring can be done better, but its much more work. Set some dry, wet it, compress it, set more dry, wet it, compress it, continue til full. The reason the dry pour isnt as solid is because its not compressed/theres too much air in it. You can hear that when he hammers the two. With wet pouring, its compressing as your mixing, and as your pouring because its heavier.
Thank you for doing this. All the other dry pour videos I've seen made it seem like it's just as good, none of them cut the slab or tried breaking it to show how much of a difference there is.
This is the comparison I've been waiting to see someone put together, thanks!
Thank you for your work! This topic popped up frequently and no one could find a real difference. Your sort of scientific approach lifted the controversy.
Btw I found the need to binge watch your videos.
Invest in a dust mask. Your lungs will thank you in 25 years.
That's a pretty long-term investment. I'll check with my portfolio manager, but I just don't think the smart money is in respirators.
@@operator8014
@@operator8014 If you invest your money like you take care of your health you don't need a portfolio manager, you need a bookie.
@@operator8014 If you take care of your finances like you take care of your health, you don't need a portfolio manager, you need a bookie.
25 years seems like a long time but it goes by in a flash. Lung disease is cumulative and progressive. You'll have debilitating effects for a long time before it ultimately kills you.
You'd have a case indoors. Outdoor would be pointless.
Great example of how RUclips makes the world better. All the experience in half the time. We’ll done!
This is the best dry vs wet pour video I've seen to date. The cut test definitely helped me make my mind up. Will be watching the pressure test video!
This is one of the best videos for dry pour comparisons.😊
I think the two biggest issues with dry pours are 1) you end up making a concrete foam with microscopic voids everywhere and 2) there isn't enough moisture content to bond the aggregate.
The first issue results in the surface being much softer and weaker (larger chips and duller sound in the hammer test). The second issue causes large sections to chunk off of the edges and corners, which is made worse by the first issue.
I really want to see a 5 year follow-up from somewhere that has frequent rain and hard cold snaps all winter. I think that would be one of the hardest environments for dry pours to deal with.
I saved a few samples and think I’ll do a one year follow up
the biggest problem is there's no mixing with dry pour, simple as that
@@dead_redux Ok, why does mixing help?
@@t0kinl3lunts Portland cement consists of five major compounds of calcium silicates and aluminates ranging from 5 to 50% in weight, which all undergo hydration to contribute to final material's strength. Thus, the hydration of cement involves many reactions, often occurring at the same time. As the reactions proceed, the products of the cement hydration process gradually bond together the individual sand and gravel particles and other components of the concrete to form a solid mass.
@dynamicdreamsgaming8409 So, would thoroughly mixing the dry component first help to at least form a better case hardening of the final, fully cured result? I do understand that the primary motivation for doing a dry poor is the convenience and all this theoretical effort would undermine that advantage.
If dry pour made sense industry would use it everywhere
Rather like the concept of, "If masks don't work, why do Doctors ever buy them?"
@@TimeSurfer206 While I don't disagree, that's irrelevant to the current video and you know it's going to start a big argument in any comment section filled with typically right wing laborers and DIYers. That'd be one thing if you thought anything constructive could come from it, but people don't get into fights on YT for the sake of open minded, complex discussions.
All that said, it's pretty rude to the Komar Project channel to be trying to start a fight in his comment section.
No, they wouldn't because a wet pour is set and forget and no sane contractor would insure a project that relies on the owner to water the slab at specific intervals.
The problem though is it depends where you 're at.
The Wet mixing doesn't matter where you live dry area, wet area..........the results are more consistant.
Dry pour though would depend on where you're at.
I'm not an expert,nor do i play one on tv, but in my area when pouring concrete for fence posts you can just pour it dry and it will become rock hard.
But in dry areas like arizona there's just not enough moisture in the air so it wont really work there
@@scottbitz5222 A wet pour should be kept damp for many days, preferably weeks.
Thank you Mr Homar for debunking the drypour hype... And just reassuring one's confidence in the conventional wet pour method... Dry pour sure looks easier in the short run, but with falling tools one will be thankful for choosing the wet pour method... Great work! And thank you again...
Thanks for taking the time to run through all of this
Thank you for putting together such a careful video. You really show the difference in the results from the 2 methods. I have worked in construction for many years, and this shows what you get from a proper mix versus an expedient alternate.
The wet pour benefits from all of the cement becoming fully hydrated and the fluid paste creating a complete bond with the sand and aggregate. Hydration is critical for concrete strength. The mix needs enough water to saturate all the material, but it should not have too much water, creating a soupy mix.
When shortcuts are taken, a crew might make a wetter mix because it is easier to place, but it will not have the same strength as a correct mix, and you'll probably see the surface scale off later due to the excess water. The concrete should be vibrated to consolidate it and help release any air bubbles. This further consolidates the mix and ensures a good bond between all the components of the concrete. Moderation in all things, vibrating concrete is good but too much may cause the larger aggregate to settle out - so just use a modest amount.
After placement, proper curing is critical. Once the concrete has set, then keeping it damp will promote the strongest cure (Ideally concrete will continue curing for 28 days). So even though you don't want to use too much water when you place the concrete, keeping it wet, using a sealer, or covering it in plastic after it has set, will produce the best concrete. Plenty of sidewalk slabs get poured and left to dry out in the sun. Obviously this works, but giving the new work a sealer, or light spray with the hose or a plastic tarp, even if you only do it for a day or two is still better than nothing.
Your excellent video demonstrated this very clearly, thanks again for such a well done test. Sorry for the long reply, I hope it helps inform viewers. I try to take great care in my concrete work.
Yup. Exactly. When my buddy did is concrete floor in his garage, he let it set w plastic over it for a week or so, then every day for the 30-60 days (or however long required) we went out and gave it a light spray once or twice a day, and put the plastic back over it. When it was done, it was smooth as glass/ice. Never seen concrete so smooth before.
If you are going to use rebar or equivalent in a pour, it really needs to be suspended as close to the middle as possible in the pour depth (as opposed to laying on the gravel at the bottom of the pour) for it to have the effect you're looking for.
I’ve not had much success with plastic coated and plastic rebar.
@@randyhome1544 Your reply makes me think you didn't read my comment. Or did you mean to reply to someone else?
Rebars are there to take up stretching forces. When the load is in the center of the slab, the stretching will be at the bottom of the slab, so having rebars below the center makes sense.
Steel rebar will rust and break up the concrete if they are not covered with some centimeters of concrete. So if the slab is thin, as in this case, it makes sense to have rebars in the center if they are made from steel. For rebars of non-rusting material, this is not an issue.
I was looking for this comment not to be the first one. I noticed this too.
Leaving the bars at the bottom is sloppy work
Thank you for this video. I've seen so many "dry pours" used for things like a patio or even the base for a deck or something and always felt like it was a disaster waiting to happen and this confirms it. I think you are spot on. Anything like a patio or something you need a base for...wet pour has to be the way to go. Now, if I'm just needing some smaller slabs to use as a walking path or another use that isn't structural...dry pour may not be a bad direction.
Great video, I have a project coming up this summer and had considered a dry pour. I'm so glad I saw your video. Thank you!
I did also test both ways, and I'll never touch dry pouring again. I knew it was gonna be bad, but I had to see it. Good video
I have never ever heard about dry pour concrete (probably because I work with computers). I don't even realize why this video popped up. But I'm glad IT DID! Highly informative! Genuinely nice tests! It would be nice to make a beam and test how many kilograms both sustain.
Love your honesty......haha
A common trend online is to pour the concrete mix straight out of the bag into whatever mould you're using and then just use a hose to apply the water to get it to cure / harden. Lazy people just looking for a short cut to actually mixing the concrete before pouring and doing it the right way.
@@Stickerz94not because they are lazy... Cheap!
Imagine a job where you would definitely have to hire it out... You're paying mimimum double for the labour alone.
There are limitations for the dry pour method.
Yes, wet pour is definitely better, especially if building a high rise building, a foundation and an industrial driveway. Typically those jobs are so big, calling in a concrete truck is already a must.
For building a pad like he just did, perfectly fine. And if you are really worried about the strength, because it is the part is heavier than normal, use more rebar and add an inch or 2 to the thickness of your slab. I'd also suggest that the top layer of the slab (1" or so), be without gravel, and a stronger psi mix. Easier to screed out
@@jakefriesenjakehow is it cheaper? Instead of paying 3 hours of labor. You are paying 3 hours of labor and then you have to go hit it with water every hour for a day. So it ends up being twice the labor. If you are hiring someone else to do it then that means they have to stay at the job all day instead of starting the next job. It's not cheaper. The only benefit I can see is there isn't a timer ticking once you mix it. Instead you can take your time, but it takes more time and it the result isn't as good
@@__Brandon__ you save the labor because you won't be hiring it out... This is a DIY process only. Pros will not do dry pour.
Sure, you must spritz it down every hour for 10 seconds, while drinking beers. This is not laborious.
Doing wet pour, of which I've done, is has a clock ticking, and is lots of work. (I even own a concrete mixer) lots of work.
I'm not saying that I'd build a house foundation using the dry pour method. It has its place.
Many people have done this and are very happy with the results and cost savings.
Thank you so much for doing this. I have been wondering about this. This is a great video explaining the difference between the two
THIS IS THE VIDEO I NEEDED. THANKS FOR THE COMPARISON 🙏🏾
I noticed that your test pours had plywood floor. Part of the tech here relies on wicking water through the ground. I’m an engineer and noticed this difference in the test.
Needs a re-test with proper water amounts and better ground surface.
Good observation. However, the top where he hit it with the hammer was weak. The soil wicking is for the bottom half. The top half is supposed to get gravity soaked by the hose. I doubt the wicking will wick all the way through to the top.
Engineer. What kind of engineer?
Software?
Mechanical?
Fluids?
Civil?
Train : D@@highlandermachineworks5795
@@SeanBlader The dry pour is just sand that 'melts' in water surrounded by said water. The wet pour is the same sand, but mixed so that the sand actually sticks to sand directly.
It's obvious that the dry pour has less strength. The grains of cement aren't actually stuck to each other fully. The dull sound comes from the fact of there being plenty of empty space with miniature amounts of air in-between the individual grains simply because they were never compressed with each other with any force other than their own weight. No amount of retesting will change physics. More contact of sticky substances = more adhesive power and more mixing = more contact. It's as simple as that.
Mr. Komar - thanks for the objective comparison. A few tips to improve your future concrete projects: 1) place bars or wire mesh on chairs instead of the ground. 2) measure the volume of water you add to the mix (you'll never achieve the 4000psi design strength if your water/cement ratio is too large). 3) After screeding/finishing, cure the concrete by keeping it moist (either with burlap, misters, or a chemical curing compound.
Great adds - esp measuring the water volume. I only just figured out the importance of that to getting the target PSI after speaking to a firm who make cement (on a long truck) to order on site.
This is very good to know! Getting ready to pour a small slab for my grill to set on. Thanks!
for like a year been looking at dry pour and thought it was the way to go .... but now ..... nope .. glad I waited
A great, real-world test with definitive results. Thanks for this.
It's not a real-world test as you never pour a concrete slab on plywood, you pour it on gravel and water wicks up from the bottom and down from the top.
Basically, his a/c slab and his test slab are not the same and his a/c slab is likely almost as strong as his wet pour
@@scottbitz5222 You do when you pour a slab for a second floor, or mold like a foundation...
I'm not sure why RUclips's algorithm suggested this video because I'm not a builder but I enjoyed it, particularly your narration. There's one small problem with your test pieces: you had wood underneath. This will have prevented (or reduced the capability of) the dry pour piece from pulling moisture in from underneath.
The both test pieces had the same frame, if that was the case, the wet pour would have failed too. Not only that, but the larger pads are poured on top of gravel, the gravel is the shed/drain water, therefore the concrete wouldnt be wicking/pulling in moisture regardless.
@@jacksmith2315 The difference in the test pieces is that the wet pour did not need to draw in moisture whereas the dry pour did. You're right about the main pieces, of course.
This is exactly right. Thats why its recommended to hose down the sub surface before doing your dry pour.
@@QuentinStephens i dont think that would have mattered. It wouldnt wick enough to make a different. The dry pour doesnt get mixed/packed enough, which is why it sounds so hollow. Dry pouring is jsut not a good idea. Why keep babysitting it and spraying it every couple hours when you can just mix it once and be done w it? Its kinda kind bondo. If you spread the bondo then just put the hardener, its not going to harden evenly, and is going to have too much air in it because it wasnt mixed. Dry pouring is just not a good idea no matter how you do it. If its not structural/holding a lot of weight and you dont care if it last long, sure. But why not just do it right and not worry about it?
Thanx for the information. I'm going to pour a base outside for my manual tire changer, and now i know the finer points.
I could tell I was gonna love your content the moment I saw the authentic moments in the intro!
Could it be you didn't use enough water in the dry pour?
The color difference and the chalky, clay like, attribute makes me curious.
That's what I suspect as well. I have seen other videos where a dry pour slab did not chip at the edge and took expanding sleeve anchors and even Tapcon screws just as one would expect w/o chipping out or cracking.
Nice job on letting cure for 90 days.. your the first to wait that long that i have seen. Now need to find your compressive strenght vid
90 days is nothing, concrete takes years to age properly. And while correctly mixed concrete will continue standing, the "dry pour" will have been replaced 5 times.
@@shinobuoshino5066 Yes, but no one really cares about what it will eventually reach for typical residential and commercial jobs because we will use it soon. It reaches a large amount of it's strength in the first month so we are interested in knowing when it is safe to build on it or use it and then the time frame to test the core samples. We do set fence posts on government jobs with the quick setting concrete but we do alternate between adding dry mix and water and mix with a shove enough to get the water all the way through. Then again, we would stretch barbed wire the same afternoon or the next day, or set gates on the posts the next day. Yes, I will stick to wet mix for anything other than fence post holes. The dry mix seems more like sandstone because the components are not blended to make a uniform cream. The granules stick together and bind the rock, but the "glue" is not formed.
@@CGT80 back in my day, posts were premade in factories instead of being mixed on the spot...
@@shinobuoshino5066 Are you talking about posts made of concrete? .......... We use galvanized steel posts and set them in concrete.
We don't need to wait for a compressive strength test because it's obvious the dry pour has next to no strength just from his hitting it with a hammer.
Dry pour worked great. On day 2 we soaked it and kept the framing on for about a week until we needed it out. We soaked it every day with the shower mode. It has not cracked or chipped and it’s been 1 year with cars driving on it.
Fabulous demo!! I always assumed that the dry pour was an inferior way to pour concrete slabs...nice to see a video that proves it! Great job 👍
I'd like to see what the difference is between wet and dry when anchors are installed, like Tapcon screws or sleeve anchors.
I’m going to add that to the next strength video. Good idea
Ive never even dreamed of doing a pad with dry pour... but did use it when doing fencing... drop it in dry spray some water and fill it in... I also live on Florida so the ground is fairly wet only 2 feet down so it gets a ton of moisture under ground while curing plus isn't ever visible so looks never mattered.
Curing isn’t drying
Curing is a chemical reaction of the lime in the portland
That is why they can pour concrete footing under water.
And it’s wet mixed not dry.
Expect to replace your crumbling Fence footing within 10 years
So your building it twice
Not to mention the demolition and haul off of material. So it’s not a better or easier method
Me: 64 year old retired pool builder
Thank you from saving me from making a dry pour mistake. I’ll be wet pouring for my application!
Thank you for the information! It looked non bias as fair as you could be. Wet pour seems to win those test!
I do feel that part of the problem with a dry pour is the sand and Portland cement separate. IOW, the finer the particles rise to the top and never fully blend into the mix like they do when you stir it up with water.
Spot on
Most people don’t understand the curing process is not just dry, but the forming of crystal structures
If your ingredients aren’t mixed they won’t bond correctly
I ask the people that advocate fry pour.
Do you just pour cake ingredients in a pan and bake.
But thinking and mixing seem to be above their abilities
Thank you for showing this! Great analysis and will definitely help me with my future projects. You devoted a lot of time and effort to show us rookies which pour is stronger. Very much appreciated!
I just did a dry pour yesterday. Ill be uploading later today. I did mine alot differently though. Great video. Thanks for sharing.
As the Gastroenterologist would say, $hit in, $hit out! You just proved their point!
In the kitchen, there is a reason we sift the flour prior to mixing the batter.
There are probably hundreds of other examples, but shorting the concrete process is not going to end well for the end user.
One of the keys is that the cement should be added to the water and then mixed to the proper consistency, not the other way around. Just like when making batter, if you add the liquid ingredients to the dry ingredients. it just immediately curdles and no amount of mixing can make a fluid mixture all the way thru. You will have lumpy bread.
That situation is exponentiated with the concrete.
"Shake well before using"!
Thanx for the video and the ultimate truth.
That dry slap reminds me of packed dirt more than concrete. Could be that it requires much more water over long periods and curing time is a lot longer.
What we have here isn't correct from an engineering aspect. Concrete is defined as the mixture of aggregate, cement and water. Not the addition but mixture. Don't use any dry technique whatsoever for any application. I'm glad that you did the comparison for edification sake, well done.
This guy did an amazing job. I’ve never seen anyone put this much time into an hvac pad. It’s not necessary but if you have the money go for it
A big thank you from Seattle as this video was both super helpful and informative 👍😎
In a past life I used to work in the oil patch. For walkways in muddy sites they used to dump dry mix on the ground and lay ply wood on top, no water added. When it came time to move you needed heavy machinery to break up the "sidewalk".
Sorry, but I got stopped at the "past life". How far back was that???
@@alexfullmer470720 years ago.
Something being cheap and fast for low tier jobs in shit conditions where road quality doesn't matter doesn't really change the fact that noone should do this for their walkway.
I only use the thing like 1 or 2 times a year, but i will NEVER regret buying my electric concrete mixer. Its the perfect height to drop the bag on the little arm that you cut the bag open on and you move the lever a little and it basically sticks 4 teeth in where you cut the bag and basically flips it over an into the hole for you. Its so nice, and when i get the mix the consistency i like, i open the bottom hatch and it'll drain out, even while its spinning if i want it to.
I try to find reasons to pour concrete just to use it sometimes. I can't even lie, totally guilty of seeing bags for cheap and convincing myself I've always wanted to do something I just at that moment started thinking about doing... Just to use a friggin' tool...
Husband & I planned a huge backyard concrete project. The 2 used concrete mixers we bought have paid for themselves many times over already. Even for just 2 bags of concrete I'd rather not mix by shovel & back- just throw them in a mixer with some water.
Great video. I have always been suspicious of dry pour. Great to see it tested
Fantastic comparison video, and this helped me make my deciding to do a wet pour for my whole house generator, especially because of your comment about anchoring behavior!
Interesting for sure. I think the dry pour is more like aircrete in that all the air voids that would be closed by wet-mixing, and overall bonding would be of course less. Thanks for taking the time to do this experiment and sharing.
I think you are correct.. they looks like fully cured but they are not...also dry pour has lower strength compared to regular wet one and i think even with time and years it would not improve much. So once it isn't done properly at the beginning you can't fix it later on :)
Does my head in how many Dry pour vids are out there. Thanks for educating everyone.
Dry pours are for Hacks/cowboy's
Thanks for your tests,
you help me make my decision
I don't understand the appeal of dry pouring. Dry pouring requires a significant amount of additional prep/curing time (if you can say it fully cures) whereas wet pour, after mixing and screeding, you're basically done. I don't see any pros to doing a dry pour.
You got to see it years later. Check the people from Louisiana who did this
@@DJRenee can you provide some links?
Man, I could smell the dust through the screen when you were cutting.
Me too.
Good Vid! I don't know who would have ever expected dry pouring would be a good option. Except for fence posts.
Place a piece of open cell foam over the dry pour. Keep it wet for 3 weeks. Initially, the water will travel through the dry concrete and fully hydrate it. Keeping it wet for three weeks will eliminate cracks and give it the best compressive strength. Not enough or too much water is resolved, as the concrete will only take what it needs.
If you have ever poured concrete underwater, you will understand.
So now after three weeks we can start walking on our side walk. Great, I was hoping for a month delay. 😊
Brother, you are a true scientist. best demo I have seen. Thank you.
First class video & audio and excellent slab prep! The sales rep for the ready-mix company who supplied our jobs for forty years always said: “We offer two guarantees, our concrete will get hard and it will crack!” He was grinning, but he was dead serious too. I do have a few suggestions and verrry strong recommendations.
PLEASE always use a good dust mask when cutting/sawing concrete and masonry materials: silicosis is no joking matter! A mask when pouring the dry mix out of the bag is also a really good idea. Safety glasses, gloves, and hearing protection are also excellent items to preserve your health for the decades to come in your life.
NeVeR use a grinder without a proper guard. The damned things are useful as can be, but would just as soon cut off your nose, toes and all points in between, and faster than it cut those blocks of concrete.
Tapping all along the sides of the forms will eliminate most of the air bubbles, commonly called bug holes. Your comments about the relative roughness of the top surface of the dry-pour are right on. This roughness is very likely to get worse over a series of freeze-thaw cycles in the winters to come. Adding water to the top makes that surface weaker, less resistant to freezing, which will result in more flaking and pitting.
Concrete is weird stuff; it has to all get wet to start the chemical reactions that bind it all together. Too much water will make it a lot weaker. Not enough water or incomplete mixing will yield what you’ve shown in the dry mix sample. Then to make it all more difficult, the longer the water stays in the concrete the stronger it will be. So on sunny or windy days you have to take extra steps to protect it. Never let it freeze, that’ll ruin it completely, worse than the dry pour.
Dry-pour is a really bad idea for a host of reasons, some of which you describe so well in these videos. Thank you for all of it, especially the break tests.
P.S. 30 days is plenty of time for concrete to cure unless the temps are below 50 all the time. It should reach about 75% of its design strength in less than ten days.
Cement mason here, thank you for making this video (you did a great job fyi, no notes). The reason the dry pour acts that way is due to overhydration. It's fully cured and nothing can fix it.
Im not 100% sure on the science of how over-hydration weakens concrete, but the results are obvious. It leads to flakey and brittle concrete that doesn't adhere to the aggregate. That's the reason chunks were flying off, the cement and course aggregate didn't bond properly.
I'd bet money the middle of the drypour is significantly stronger than the top or sides, but is still weaker than any portion of the wet-pour concrete. The top of a dry pour will be the weakest, hence why your hammer did so much damage. I suspect the middle would take a few hits with a little more grace
Also, you were very correct about rebar. Any structural concrete needs rebar or other kinds of reinforcement, even if its touching the ground. Physics are weird, but basically when weight applied to the top of the concrete, there's a small tensile force being applied underneath the slab. If there's no rebar, that small tensile force is enough to make a small crack. Over time, it'll widen enough to be seen by the naked eye. For those unaware, tensile force is basically bending. Rebar-reinforced concrete is a sum of its parts, having nearly the tensile strength of steel alongside the compressive strength of concrete. It also slows the time to failure (ie the time it takes a comprised structure to fall).
I am a massive nerd for this shit xD
Hey I wonder if the test is the problem. The test was in a sealed bottom, but the ac pad was open to the earth moisture to wick up into it. How about doing an open bottom test on the ground for dry concrete. I'm not a big dry fan but iv done dry post settings and later pulled them out and they were set and cured like regular cement
And that effects the top of the slab how?