Dry Pour Concrete: How Deep Can you Make it? 

For everyone saying there wasn't enough water and/or a week wasn't long enough to wait, I cracked open a piece from a different dry pour project three weeks later (total of four weeks after pour). Check it out here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-7FKddDUtr1g.html

When I do 3 foot deep fence post dry pours, I do a few important things differently: 1. Tamp as you go. Tamp the mixture together as you go (as you add) to eliminate voids 2. soak the area for a long, long time. I would put maybe a sheet of newspaper on top to keep the surface from being pitted, but since aesthetics aren't important I wouldn't stop hydrating from the start 3. I would just leave a slow mist or drip on a column like that, continuously hydrating, for a good 24 hours. Concrete is like a sponge and the water will get all the way to the bottom. We are naturally impatient so we want to just drench but the absorption rate is slow. A continuous mist that doesn't drip water directly onto it works fine. Set and forget until 24 hours. 4. I protect from drying, or just keep wetting it for a good long while.

Dry pour internet videos: Let's break this open after 15 minutes so I can publish the video already.

I don’t think you need to mist it if your not concerned about aesthetics. Just flood it

Thx for trying this but I'm not sure why people keep only estimating the amount of water used when they should be using the amount of water for each bag. For every bag of concrete, people SHOULD have a measured amount of water set aside to pour on the surface after the top layer firms. This is the only way to know how strong a dry pour can be because of actually using the correct amount of water for the entire process.

I see there are a few things that would have made this a success, I am NOT a professional but I do have experience with regular concrete. I noticed that when you started with the water that you were following instructions for a pad/large flat surface where you didnt want to upset the visual look. What I would suggest instead is to immediately add water and avoid the misting because this isnt 1-4in of material that needs water. This shoud have been watered down from the beginning so that the water had time to get to the bottom more evenly. Other than that I believe that letting it sit for 2 days after watering it that would have been a much better comparison.

I think for that particular shape, I would have just go full soak instead of waiting an hour between misting. Since the mix is a lot of sand, most of the water will drain off into the ground and whats soaked into the concrete will cure well. The crete will only accept as much moisture as it will absorb. The sand in the mix is the best draining medium. Of course a psi test afterward would test how strong the cure is. Crete will cure hard with just about any amount of moisture. Getting the correct psi depends on the amount of moisture, time, and evaporation rate. This is my uneducated guess based on sculpture work with crete.

The misting method only is used for 4 " to do that kind of pour you would have to totally mist it till it's totally drenched because that's to far for the water to reach the bottom at that point for strength you would have to stay and continually drench it

Isn't the thinking with drypour that the cement will absorb water slowly over time? Since you isolated it from it's surroundings the only water it got was from the top and bottom. Is 2 days do you really think the cement got enough water from either direction even if every drop you put on it got absorbed?

A 19" slab? Who needs a 19" slab? As much as you tried to resist it i think for a foundation pillar you'd want to get the concrete in direct contact with the surrounding ground and have that soaked. My understanding is concrete is porous and water will slowly move through it Maybe you should do a slab pour where it goes from a few inches to a few feet thick, leave it a really long time - at least a month, if not several - during a time when there is plenty of moisture available to soak into the slab gradually. Then cut sections of the slab at various thickness and have them professionally tested.

Awesome! Thank you for spending the time and money to conduct the test again as many viewers requested. The video was very informative. I was curious how much of the bottom of the tube had cured from contact with the ground, glad you showed that part. I am slightly curious how the test would have gone if the tube had been fully submerged - would the interesting to see if the cardboard would have been soaled over time etc. But that doesn't matter much as no one is going to wait that long to use a pilon. Thanks again!

2 days is not enough time to fully cure a 4 ft pillar

6:46 how much water per cubic inch did you pour. For that depth, you would have had to fill that top section 10 or 15 times to have enough water to soak to the bottom. Without the proper amount of water and curing time for the amount to mix, it is not a really fair demonstration. Not adding enough is like not adding enough water to dough. But still 19 inches is not bad at all.

You really should do this and let it sit outside for a month or so. Fence post seem to get really hard after being in the ground for a long time. Also consider the red bag fast setting quikrete mix which says on the bag that it can be dry poured.

Sure if your building a 4 ft thick bomb shelter, bridge, high rise etc. dry pour no good. But for the small DIY home projects dry pour is fine.

Good test now it's a dry pour test , i knew dry pour would not work for anything thicker than 6" . Even if it works mixing gives a better psi rating. Thank you so much for the test .

I guess everybody needs to do a video on this and it was somewhat interesting to see this one but I don’t think anybody would even consider doing a dry pour more than I would say 10 inches max.

Did you water it well 4-5 times a day for two weeks as you're supposed to do with a normal wet pour. If not, it does not settle it at all.

I am doing some stepping stones. # inches should soak just fine. I'll moisten the ground first so it soaks from both top and bottom.

The reason you were able to pull out the bolt and destroy the concrete, is you didn’t give it enough time to set up and harden. You can’t just do everything in 24 hours, you need six weeks of setup time for it to work.

Totally acceptable to tap sides to destroy air pockets in my view, but comparison to a shallow slab very different test

Since the concrete is in a tube and contained, you didn't have to saturate the concrete a couple of times. You could have just poured 1 1/4 gal of water slowly, for a 60lb bag of concrete.

excellent science experiment ..

For it to mix well dry pour is still mixed when you pour it but to make a tube you would have to totally drench it all the way through the difference is to make sure when doing this way is to totally drench it then come back in 1 hours and doing it again 1 hour drench 2 hours drench then fully water it let the water drain then do it again then repeat wait 2hours and drench one last time

Would it had helped if you used Quike crete?

Did you put the amount of water written on the bags?

Thanks for showing this. I think it would have been better to just soak it from the beginning. It might have worked. I'm just going to mix it. I don't see this method saving any time or effort. I certainly don't want to chance it. The foundation is the most important part of a build.

Recommend demonstrating using an a small slab. ex. 4x6x4(?). The PSI strength should be on the bag.🤷🏾‍♂️

You're supposed to repeat the shower twice for every inch of slab. So a 48" slab would take 96 hours. If you were able to do that straight through at 8 hours per day, this project would not be complete for 12 days. That's why it failed.

Lack of water, no curing time. Great method 😂

I haven't seen anyone try to do a full tube of dry pour. 6" max depth maybe. You'd need to add water every bag or 2. In a dirt hole for a post, dry pour is completely fine. Don't need a tube. Even then, the entire depth (4' in Michigan) doesn't need to be filled with concrete. I would do 2 bags at bottom and 1 bag at top. I wouldn't even use a tube for a footing except a section at the top to get the concrete above grade and level. I'll be trying to do a dry pour on bare ground over a horizontally laid tube to extend my drive way culvert a few feet. Will be about a foot of gravel on top of the concrete. 12" culvert pipe is way over priced if you can find it and I don't need to buy 20' to only use a 3' section.

5:21 but how long did you allow it to cure?

Cue the "Where's your mask?!" comments 😂

First I want to say thanks for the test and video. However I feel there is some problems presented here. Dry pour for fence posts is used all the time. I think the way presented here doesn't do dry pour any justice. It gets stronger over long periods of time. Eventually it will have full coverage and the concrete will fully harden and cure close to max psi strength (over one month). Doing a 24 hr comparison is basically a worst case scenario between the 2 methods. Even wet pour after 24 hrs to me is very weak and brittle. I have had to wait over 2-3 days before removing wet pour from concrete molds, etc. Also your curing and drying explanation is very incorrect. Copied from the internet here is a guideline for wet pour (conventional). When waiting for concrete to dry, keep these timeframes in mind: 24 to 48 hours - after inital set, forms can be removed and people can walk on the surface 7 days - after partial curing, traffic from vehicles and equipment is okay 28 days - at this point, the concrete should be fully cured Dry pour takes longer (as the water penetration is not as fast and complete as wet pour) I have many dry pour posts that if you pull them out of the ground, the concrete around those suckers are just as hard and strong as the ones that would be wet poured. The problem I think in this video is time and water penetration. Had the tube been set in the ground and the wet ground was giving moisture from all sides it would yield much better results. I understand this is a test but I believe the testing methods here is flawed and give poor results.

thx!

Dont give up! Do one more test. All it will take is another not-fun clean up and goodbye to more of your own money! Hopefully this will produce more accurate and desirable water/concrete mix results than your last attempt using a hose and spray nozzle, which can't be easily measured or delivered. Also will provide evidence of how water does or doesn't permeate a volume of dry concrete mix that's thicker than a 4" slab configuration. Quickrete specifies 7 pints of water per 60 lb bag of the mix you used. As before, fill another 8" diameter x 4 foot Sonotube but with only two 60 lb bags. The column height will be about 31". No need to tap or vibrate. Then pour in all the ACCURATELY MEASURED water that Quickrete specifies for the two 60lb bags; 14 pints (1 gallon +3 quarts. Not from a hose, use a container. Let cure for 24 hours. Cross fingers, cut open the cardboard tube and destructive test.

If you had watered in between bags and not run 30 gallons of water through the top layer washing away any strength. Also it takes a week or longer to cure. You said concrete is cured in two days

For a form, just pond the water on top. Once it all sinks in, repeat. Keep doing that for 28 days ...

Miss ya at the Lab bro!! die antwoord!!!

Soak the tub? You said cardboard so it should penetrate inside. I would have put some water inside as you poured in bags. Cure for weeks

I honestly dont think people are trying to make 4ft columns with the dry pour method. The regular way of mixing concrete or bringing in a concrete truck. Is how 4ft piers and house foundations are made. People have made shed pads, sidewalks, carport slabs and so on. So 1"- 4" slabs done the dry pour way is great. I will be making a 3"- 4" thick parking pad on my off grid property using the dry pour method. When it rains it's too muddy from the truck to my mobile home.

Many thanks to Appalachian Wood for conducting this experiment, it was very enlightening and educational. IMHO comparing dry pour to wet pour is the same as comparing a Harbor Freight trailer to a flat bed. Dry pour is fine for small DIY projects, however no one in their right mind is going to want to build a multistory office building using dry pour with current technology. On the other hand, why pay contractor rates for a home sidewalk or garden shed slab when dry pour is fine. Plus, why miss out on that personal satisfaction of doing it yourself. Wet pour is for commercial projects and the overwhelmed, lazy, and/or timid homeowner. Dry pour is for the cash-conscious do-it-yourselfers. Everyone just needs to stay in their lanes.

1 - Roughly 5 quarts of water is needed per bag, you might have done one total gallon. 2 - Light moisture turned the dry concrete gray deep inside and it never got enough water to actually solidify. It needed to be actually wet. 3 - I wouldn't hammer an anchor into wet poured concrete until after full cure of 28+ days. 4 - Cylindrical type containers are going to allow water to leach quicker and further along the sides, then in the center area, thus causing the center area to only get moist - not wet as required. 5 - No amount of water would have leached down 4 feet in the time given. 6 - No person would try and fill a column dry that tall for any structural purpose. 7 - If pouring a column even wet, you must use rebar over 12" depth or it will crack/break just like the dry pour. 8 - Only a person that has never mixed concrete would believe this video.

24 hours???

Should have put water into a container so we could see how much water is needed.

The only thing I see differently is in every other dry pour video I've seen they use quikrete and not normal concrete, and they did every hour or two not 20 minutes,

Blaming the system when you don't follow directions is not a fault of the system, it is the fault of the user. Clearly you have not watched enough of Cajin Country Livin's videos of doing dry pour, as you did not follow the basic rules for wetting, at all. They say you need 2 showers once per inch of thickness of the pour spaced out by 2 hours each. (See ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-_50MXEHr678.html) which would requires days of showering to fully wet the concrete and trigger the chemical reaction that causes it to harden. I imagine in this specific application that placing a micro-drip waterer on top and running it continually for a couple days would probably be okay after the second shower and would result in full penetration of the water in sufficient quantity to fully wet the concrete mix. BTW, using a oscillating saw (saber saw, saws-all, without a blade is a great method for vibrating a form to get the material to settle, eliminating voids.

“Remember curing happens in 24 hours drying is about 28 days per inch” literally BOTH are completely inaccurate.

Manufacturers state takes 7 days to cure

2 days is nowhere near sufficient. It takes weeks for concrete to fully cure In addition, concrete should be tamped down firmly. Obviously, such a large depth of concrete needs lots of water.

It's needs to cure a day or more to use a anger both

dry pour should not be used for foundation. or any thing with weight bearing like a dry drive way. may be

dry pour in the manner that you are doing is for posts in the ground. you would dig the hole center the post then dump the concrete in and soak the hell out of it. over time you will get rain and watering the yard and snow and everything else. you need to redo this and soak the whole thing and let it sit for a long time getting it wet a lot over time. this test is nullinvoid

5:30 " the concrete is cured" No, at two days the concrete is nowhere close to cured. The failure indicates insufficient water. Best to put a drip irrigation on it and keep a pond on it. The advice to do layers for dry pour is based on what? IMO it will not produce a strong foundation. The general rule for curing is 7 days for a fully hydrated paste which produces 70% of rated strength. See American Concrete Institute ACI 308R-16 "Because hydration can proceed only in saturated space, the total water requirement for cement hydration is approximately 0.44 g of water per gram of cement plus the curing water that needs to be added to keep the capillary pores of the paste saturated" (pg 3) Thus, if the form had been properly hydrated, you would have seen moisture seeping from the bottom of the form.

I'm not to convinced by your experiment. I noticed several flaws in your process..

Why waste your time on dry pour and spending 8 hrs pouring concrete and sprinkling watering when doing it wet you'll be done in 3 hrs duh

The question for me is: are the any situations where dry pour is superior? I can't think of any. Traditional is so much more workable and not really any more difficult.

Wear a mask. That concrete dust is very very bad on your lungs

In this experiment you are basically testing its abilities as a foundation, therefore aesthetics are irrelevant. I think the main issue with this method is the lack of water in the required time. If the purpose is to show its suitability for foundation work then I would conduct the experiment again, but this time fill the tube to 3 foot, drill some 5mm holes every few inches around the entire tube and and all the way down. This will allow excess water to leave the tube (just like it would in a trench). Then drape the hose into the tube and let it run slowly for a few hours until it stops absorbing water. After at least 48 hrs, open it up. I don't think that premix is any good for a foundation anyway to be honest. It would be much better to mix your own dry mix with the correct ratio of cement, sand and gravel. It would also be much cheaper.

I dont think he knows what hebis doing

Lmfao wtf is this. A mist is supposed to wet all the mix. Lmfao. He shouldve sprayed alot in between bags. Who would think thay a mist is going to wet all that ready mix

You REALLY should be wearing a proper respirator when pouring bags of dry concrete. When the dust gets into your lungs, it mixes with the moisture in your lungs, and then does what concrete is supposed to do. Not only can that make your life pretty miserable, but your wallet and health insurance policy won't be very happy with you either.The only aspect of this test to be a fail, would be the test itself. Dry pouring a four foot by 8 inch form tube is not a realistic test, and every one of the tests and inspections of this form tube proved it. While dry pouring is acceptable in certain situations, it is DEFINITELY NOT acceptable for something like this, which is meant to be a structural support. Next time do a test with a 4 inch or 6 inch slab.

You didn't leave it to cure long enough!

You need a check up from the neck up