Anyone had concrete slab leveled/stabilized?

[coloradobluesky]

Seem to be two methods. Mud jacking and polyurethane foam jacking. I want to stabilize a sinking slab that is on soft (poorly compacted) ground. I say that because it is sinking.
Any advice or experience out there?

 

[brian]]

Unfortunately. In our case, it was the clay in the Mississippi delta- expands in the wet seasons (2) and contracts in the dry seasons (2). The footing broke in a couple of places.

There is a solution for this as well. Here are the options I'm aware of:
- mud jacking to fill voids under the slab
- jacking the foundation and inserting new concrete
- jacking the foundation while pushing a pipe down to more firm strata- kinda like an oil rig but with a hydraulic jack.

All options are "spendy".

 

[Matthew]

Will be trying the foam-jacking/poly-jacking on Monday. I'll let you know. I my case, it's where the front sidewalk meets the front porch. We had that section replace about 5-10 years ago, but it sank again. The polyjacking guy said it would be no problem to foam in the void under the porch, raise the sidewalk, and give us 3-year warranty. Price was roughly $250 for lifting the sidewalk and another $250 to fill the void under the porch. Cheapest repair we were able to find.

I know it's a small project compared to what you have.

Piering or hydraulic jacking (or whatever it's called) is expensive and invasive. A neighbor did that on a project of his.

One of the advertising deals on foam-jacking is that the foam is so much lighter than the grout used in mudjacking that it ads very little extra weight to what the soil underneath has to carry. I guess that's good.

 

[AKBill]

Part of my driveway has sunk. Interested in the topic to see if it applies to my case. Not sure it's even available in Juneau. Good luck on your repair.

 

[chartbundle]

I had the foundation of the house repaired, part slab, part conventional foundation. I don't know if they did any of the mud stuff on the slab as I hadn't moved in yet, but they did sink piers around the outside and one in the middle of the slab. I haven't checked to see how level they managed to get it, I'll worry about that when I redo the floors, but as long as it passes inspection if I ever sell it was worth it.(about $20,000)

 

[Matthew]

Mud or foam jacking will require holed drilled through the slab. Mud needs larger holes than foam.

 

[denverpilot]

I'm trying to decide what to do in my garage. Karen's truck has caused a warp in the concrete, so it probably wasn't compacted correctly under there.

It creates a little swimming pool of sadness in snow season when her truck melts snow and ice off in there, that moves to and then sits right under her driver's side door.

I'm cheap. I'd just back in. LOL.

Plus, it would be nice to get that floor level and then epoxy it. The epoxy and chips thing makes for a pretty nice garage floor.

 

[FORANE]

I had a slab sink at one side of my garage. I had my backhoe guy dig directly adjacent the slab. We found a large rotting tree stump and pulled it out. Then I dug in a few locations under the side of the slab, put cap block in the ground in those locations, and jacked it myself. I used 30 ton bottle jacks available here:
https://www.amazon.com/dp/B005FYM5W2/ref=cm_sw_r_cp_dp_T1_tZ5tzbRRG3N1B
After jacking the slab to about level and filling the jacked locations with cap block to keep it there, we called in a concrete truck to fill in the entire area dug by the backhoe, around the dugout spots and under the slab.

 

[Hank S]

I'm trying to decide what to do in my garage. Karen's truck has caused a warp in the concrete, so it probably wasn't compacted correctly under there.

It creates a little swimming pool of sadness in snow season when her truck melts snow and ice off in there, that moves to and then sits right under her driver's side door.

I'm cheap. I'd just back in. LOL.

Plus, it would be nice to get that floor level and then epoxy it. The epoxy and chips thing makes for a pretty nice garage floor.

I'm cheap too, and I put the beige Rustoleum kit with fancy color chips in my last garage. Two things I learned:

• Don't paint much before sprinkling chips, they don't throw worth a durn.
• Epoxy paint is very slippery when it, or your shoes, are wet. Add some wing walk grit when you mix it hp, and stir frequently!

As with all painting, life is all about surface prep. The kits contain everything you need except a mop (wash, rinse, mop dry, acid etch with disposable mop, rinse, dry completely) and rollers. Good luck!

 

[denverpilot]

I'm cheap too, and I put the beige Rustoleum kit with fancy color chips in my last garage. Two things I learned:

• Don't paint much before sprinkling chips, they don't throw worth a durn.
• Epoxy paint is very slippery when it, or your shoes, are wet. Add some wing walk grit when you mix it hp, and stir frequently!

As with all painting, life is all about surface prep. The kits contain everything you need except a mop (wash, rinse, mop dry, acid etch with disposable mop, rinse, dry completely) and rollers. Good luck!

Good tips. I need to get it not to have a concave little depression first... but will keep that in mind.

 

[Matthew]

This is the stuff the foam-jacking guys will be using on our small section of sidewalk and porch later today.

http://ncfi.com/geotechnical/

I got the "before" pictures yesterday. I'll get the "during" and "after" pictures today. This is a really small, simple job so there shouldn't be any surprises. When the guy showed up for the quote, it turned out he's the owner of the company. We ended up talking for over an hour, then he pulled out his ground penetrating radar and scanned my garage floor for me. He found voids, as expected, but said they were not a problem because he also found piers supporting the slab.

 

[Matthew]

Well, it's done.

I didn't expect it to be magical, and it wasn't. That stuff works pretty well, but I think I realized that floating small things like my sidewalk can be a bigger challenge than a larger slab or entire driveway. The sidewalk sections are more affected by the way the soil has settled or heaved beneath them and that can cause them to rock or tilt to one side. That happened to us. One of the sections lifted OK, but then tilted. To match the edges, they did raise another section slightly, then had to grind off the high corner. Not a big deal, but something they don't want to do because it means something didn't go right.

I couldn't get "during" pictures because there wasn't a whole lot to show other than a couple guys with drills and saws and hoses. They used the saw to cut a smooth gap between the stationary and moving sections so they'd slide easier.

The pictures show just how much settling occurred to the surrounding soil after all those years.

Before pictures. The edge against the house settled >3 inches, and the edge away from the house rose >1 inch.



After: They raised the front to it's original height (or within about a half inch), then patched the seam. That seam was where they ran the saw to smooth out the edges so the two surfaces didn't interfere as they moved. The far end was more of a problem because of the way that whole piece was wanting to rock on whatever was below it. They coudn't quite get the angles to match, so they ground off one of the corners.



Now we have to bring in more topsoil raise the surrounding areas back up to match the top of the sidewalk.