Leveling a Driveway - Mudjacking vs Polyurethane Foam (slab, concrete, washing)

[PennyLane2]

My driveway is made of large slabs of pebbled concrete, which are separated by small pieces of wood. Two of the slabs have sunk on one corner, one maybe about an inch and the other about two inches. The driveway is on a slope, so I *think* the slabs have sunk due to rain water running alongside of the slabs and washing out the dirt underneath. I'm thinking I need to have them fixed before the slabs actually break.

I'm wondering if mudjacking or using the polyurethane foam, which is applied in a similar way as mudjacking, would be best for a long-term fix. I know mudjacking requires bigger holes than the polyurethane foam, but that's not a big deal to me.

I just can't imagine either method being able to lift up that huge slab of concrete even though it would just be on one corner of the slab. I'm thinking that a tremendous amt of pumping pressure would be required with either method. I've watched the videos of the foam method, but I'm still not sold.

Anybody have any experience with the foam or mudjacking to level a drive? Any opinions on which would be the better fix?

[TrapperL]

Either method is at best a temporary fix. Being that you are in Texas, your soil is most likely clay. Most any house in Houston to Dallas to San Antonio is sitting on unstable clay soil. The soil virtually moves like the blob when it rains. Look at it like a sponge, when it's dry it shrinks. When it gets wet it swells. You can have up to 16" of vertical displacement with these soils and that means the ground is actually going up and down 16" from the driest to the wettest conditions. You don't see it because everything around you is doing the same thing. Probabilities are high once you pump it, it will happen again. A better fix is to remove the panels, pull out the soil under it to at least 12", preferably 16", bring in PI 17 or less compacted aggregate and then repour it. That usually works but there's no guarantees with flatwork.

Should you decide to have it pumped. They do not need to drill holes in it to pump it. They can come in from each side of the driveway to put in the piping. I've uses both systems over the years and I don't see an advantage in the real world of one over the other. Neither actually worked for very long and we were back to replace the panels.

[PennyLane2]

Thanks Trapper, not what I wanted to hear, but I get it. I want a long term fix, so maybe I'm just going to have to bite the bullet and have the two slabs replaced .