The guys who make a living slab-jacking are not going to approve of this as it will diminish their work and absurdly high prices. I used this method 4 years ago to for (2) 36" sidewalk slabs. Rain, feeeze, thaw, snow in NE and hasnt moved an inch.
Thank you for sharing! I am in the NE of Ohio, and mine also hasn't moved an inch for over a year. Before this foam concrete lifting project, I paid a concrete leveling company to level this sidewalk, but the slabs started sinking after 6 months.
It always helps to either saw the joint between the slabs or to ensure that the joint is clean. Any debris or friction between the slabs can reduce or even prevent movement. I've even seen slabs break just because the joint wasn't cleaned.
I thought about trying this but wasn’t sure it would have enough force to lift it. Pretty cool. I ended up using chains and bottle jacks to lift the slab and poured concrete underneath.
I’ve used it where if you can pry up a sunken section to level then, you can spray foam the void, once solidified remove pry wedge… also same as in video not with the intention of lifting the slab but filling in the void under the slab where the gravel/pebble/sand has washed away over the years. The spray foam will stop further settling sometimes that’s the only option if you can not manual pry the section to level.
I wouldn't have thought that those cans would have enough pressure to force the foam as far as it needs to go. I'm guessing that's why they drilled multiple holes so close together.
I thought about this the other day and didn't know if canned foam would actually lift concrete, but it damn sure does. not sure it will work in my situation but it gives me hope
I luckily ran out of cans of foam when trying to lift a 36 inch by 50 inch sidewalk slab. I put 2 C-clamps on the side facing my front lawn, attached chains to a 6x6 beam and bottle jacked the beam/slab up 1.5 inches to match the the other slabs. I could not grab any other sides as they were hemmed in by the curb/other slabs. The curb side was still down an inch. I drilled 9 holes and started filling the curb side first, I think that was a mistake as the foam had plenty of space to expand towards the lifted side and the curb end did not seem to be lifting. I then started to fill the holes on the lifted end to dam up that end. I used all 6 cans of foam (Great Stuff Wide Gap Exterior) that I had and ran out to the hardware store. When I returned 25 minutes later the whole slab had lifted up a little too much. (evenly) I was lucky I ran out or I would have kept pumping foam in there and I would have raised the slab up way too much. I had to raise one of the adjacent slabs a little bit to even it out, I only drilled 3 holes and did not use the bottle jacks on the adjacent slab. In general I am happy with the project but be careful not to over do the foam as it continued to lift for a half hour or so.
I had this idea re: great stuff but wasn’t sure if it would work ..thanks for videoing how to do it & that it does indeed work! Need to lift a sunken concrete slab on 1 end in my backyard that some contractor gave me a usurious estimate ( over $1100.) to break up & replace the 1 slab that is otherwise intact & stable .glad I you tube-googled slab jacking . I wasn’t sure could be done & found this video in particular.you helped old lady get smarter.
I for one am in the same boat. My patio is on a slope and the slab broke half way. No rebard was installed soooo, yeah. Well I been on youtube for like a week straight looking for some diy to fix the problem. Then, this man has blessed my game with what looks to be some really really inexpensive work. So. I'm going to try this, TODAY, lol. My patio slab is much bigger and much heavier bit at this point, I'll try anything. The wife wants it done and I need it done so the kids can go outside and leave me the hell alone. Told em I was gonna start putting their toys under there to jack it up if they dont start acting right lol. Bit any-who, thanks for the video buddy. Have a very blessed day sir! No 🧢👍
@@icyviolator5536Did you try this? If it worked, is it still good 2y later? I also wonder how much the foam continues to expand after you stop spraying.
This is awesome. Many thanks for this useful video. My only question is where the foam once cured has enough mechanical strength to support the weight of slab? And will it last?
Great idea! DId you notice that the other slab (where vacuum is) was slowly rising too? Guess that's okay as long as it's not too much. Thought about how the pros do it and wondered about this method. Thank you.
@@hcrankin5923 I raised a small 3’x3’ concrete pad roughly 2”-3” using 8-9 cans. I drilled 4 holes near the corners . Like I said in my previous post, be patient as the foam will continue to expand and raise it higher than planned.
10 cans Great Stuff? Basically trying polyjacking but doesn't address the continued sinking of the ground below, so will be sinking again. Probably wasn't built over solid base, sand, packed road base deep enough. Also water flow issues and clay soils in NW Ohio expansion, shrinkage, freezing repeated cycles...needs a base under the concrete that can flex with the freeze- thaw cycles or just expect this repair to be needed at least annually...
I tried this on a 36' wide walk way. used 4 cans till it was squirting back out of the holes, and I had the holes pressure sealed pretty good while squirting it in. It really didn't do any good, maybe 1/16th " rise. $ down the drain.Now I will try another area.I drilled the holes. Now I'm wondering if the slab might be more likely to lift if I put water down the holes and let it get damp over night. Wondering if that might help to break the tight seal between the concrete and the dirt underneath.
If you manually raise the slab/concrete to just below the flush point then inject the foam that may be enough to let it get under more of the base. If it doesn't level, let it go off then try again. 👍👍 God luck.
I’ve seen a video that shows a cross section of two separate slabs. One slab is lower than the other but they are both sunken in at the center line. There is soils under them but with gaps. The hole is drilled and filled in one slab. When filing, the foam rushes under this slab and also under the adjacent slab and they both rise up. The one that was lower actually equalizes (maybe based on equal weight?) and catches up to the other one. They both end up level and even with each other.
Another guy had a way to lever up the slab with a 4x4 by digging around it and put pink insulation foam slabs under it. Pounds per square inch seem to be much higher than this small can stuff.
Is that Closed Cell or Open Cell foam? I saw videos with someone using Secure Set foam and its closed cell. I have Froth-Pak foam in stores near me but can't tell if it's open or closed cell high density. I need to do a driveway.
I have raised many slabs with foam and jacking equipment. Was thinking about trying this just never had the time. The foam should hold due to he used the right type. It may come down eventually but that would be due to erosion which cannot be controlled except with other types of erosion control. Comment about cutting loose is a good idea to.
It’s hydro jacking with a thick fluid that eventually cures. The process is just like mud jacking. It’s the thick fluid that raises the slab, not so much the foam expanding. If it was the foam expanding, it would keep lifting for the next few minutes as the foam fully expands. Since the foam expansion doesn’t have the power to move the concrete it pushes down on any weak spots in the soil as well as fills any actual voids.
@@friendnfamily9053 Great to know. I'd call 2 years a massive success especially considering the low cost of Great Stuff. I have a void that opened along the side of my patio. Going to use your method. Doesn't require any jacking so this is just preventative.
@@trevorsmith4597 Hi, other related videos can also be good reference. Be patient and give it time as the foam can over lift the concrete as in video FnF302: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-NkM2KJf_Xcc.html
I'm building an 8x8 metal arched metal shed and looking to fill 2 inch space between my paneling and the metal exterior (Yeah I have no intention of ever taking it apart). In all I think I need to fill about Four 4x8 panels x 2 inches ( I think about 800 cubic inches). Possible with cans? How many?
Not sure if this would work for your situation as you may over lifting or break your panels. But if you would like to give it a try, you may want to go slow with 1-2 cans and wait at least 1-2 hours before deciding if you want to add more. I wasn't very patient and over lifted my other panels by 0.5-1 inch in video # FnF302, FnF303. My other panel (I think it is about 4ft x 6ft x 4inch), was lifted by ~1inch with only 2 cans (video # FnF304).
good idea, just be mindful that the foam may be open cell and will absorb moisture and eventually breakdown contaminating the soil. I use a closed cell that will not leach over time. For the 12 cans ($144) used to get a partial lift a professional could achieve entire project for same price. Be sure to fill voids away from joint to support slab and prevent crack in future.
@@yellowbellybee I am estimating walk at 4ft wide and (2 sections) 8ft long with 1/2in lift one end, would charge $100 if i could combine with other work in neighborhood. Take about 15mins. Warranty for 3 years.
Every single "pro" in my area have an $800 minimum. I just needed a void filled on a 2' x 3' slab that didn't sink or crack that water erosion flushed out underneath. Fixed it myself with 5 cans of foam and 3ft of hard vinyl tubing for $46.
In other vidoes they raise the concrete with jack, creating air pocket under path. Then fill holes with foam, but you do not raise concrete first. Is it possible there will be no where for foam to go and so not work to raise concrete?
It will sink the foam is a .5 pound foam not strong enough to last more than a couple of months. Needs to be a 2.5 lbs to 4 lbs by volume to work permanently
Hi Mikey: I used up 10 cans in this experiment. Looking back at the video, I think I could stop at 6-7 cans. The size of the drill bit is 3/16. Hope that helps!
Ok. Got a hammer drill but the longest masonry bit set I could find was 6". Where did you get that masonry bit set? Sorry for bombarding you with questions
FriendnFamily Got a nice SDS hammer drill and a 12” bit which was more than long enough. Unfortunately the foam took the path of least resistance and most of it came out the side. Tonight I figured out a way to use a jack and concrete anchors so I’ll try that and inject the foam to fill in the void. Thanks for the video!
@@HRradness I think a work around might be to fill in the edges first then shoot foam up the middle holes when that has dried? I haven't tried it but seems like it might work
Your slab is sinking still because of your yards drainage likely. Also I bet your one slab was hooking under the farther slab and couldn’t go any higher without wanting to raise the far slab too. Resistance.
In this video, I had the holes drilled ~6 - 7 inches from the other slab. I think it should work better with the holes drilled ~10 -11 inches away from the other slab.
@@Baltimore789 Having the holes too close to the other slab, the foam would have more chance to get under and lift the other slab too. Hope that helps!
Great video, but this method potentially causes a big repair cost because we don’t have any idea how much the concrete slab will be raised up. What if it’s raised up too much? Then, it’s going to be a bigger issue
Just dig out the edges on both sides. Use a 2x4 and 4x4 to pry up, use bricks to hold it in place. Fill with crush/run gravel to proper level, pack a concrete slab about the height and width of the gravel, let it solidify and then bury it back with dirt, should be good. Idea i had. Wife wants to raise slanted sidewalk lol. Ill try to remember to do a video and post to my channel. This guys video was good. He was testing. His next time will be excellent
