Failed Concrete Pilings on Residential Home

Problem

The homeowner hired a foundation repair company to install concrete pressed pilings, use polyurethane injections around their 1974 slab foundation, and have made adjustments four times in the last four years. The homeowner was looking for a permanent solution so they can remodel their home without having to worry about it cracking. Our soil data shows below the 1-2′ layer of limestone fragments that there is a 10′ layer of expansive clay soils before reaching a solid layer of limestone. In addition, there are mature trees around the affected areas where the tree roots are likely contributing to the shifting.

Solution

The breakthrough layer of limestone fragments 4-5′ deep where the previous company was unable to penetrate with their concrete pilings, and drive 38 steel piers to load-bearing strata, and fill all voids created with mud jack once the foundation has been lifted, and plumbing has been tested for any possible leaks. We will also tunnel to pier locations under the slab to avoid damaging the tile floor and will expose the plumbing to mitigate damages during the lifting process.

Outcome

After exposing existing pier locations, we discovered that most of the previously installed piers were not even 4′ deep, and the precast cylinders were broken in half to make them fit under the foundation. After removing these failed piers and breaking through the 12″ layer of limestone fragments, our steel piers went an additional 15′ deep, totaling about 20′ from grade on average. We lifted the foundation as much as 3″ under the bathroom area, freeing up the sticking doors, and the plumbing lines didn’t break due to having been exposed from tunneling the lines during the excavation. We mud jacked 15 yards of cement/topsoil mixture following the lift and backfill of the tunnels, repaired the sprinkler lines we had to cut and left everything as clean as it was before starting the repairs. The entire process took 13 days from start to finish.