Rock vs clay
Piers stop at shallow limestone on some west-side lots and run deeper in eastern clay.
01How slab repair is done
The usual fix is to install steel or concrete piers under the beams of the slab, then raise the low areas back toward level with hydraulic jacks. Pressed concrete piers are common in the San Antonio area; steel piers are driven deeper and are often chosen where clay is thick or loads are heavy.
On rock-heavy lots on the Hill Country side of town, crews may hit refusal at shallow depth, which changes the pier plan.
Read more+
After lifting, voids under the slab may be filled and plumbing can be pressure tested, since lifting a slab can stress old drain lines.
02Signs the slab needs attention
Diagonal cracks running from door corners, a step crack in exterior brick, gaps between the slab and baseboards and a floor that feels like it slopes when you walk across it are all common. A single hairline crack in the garage slab is usually shrinkage, not failure. If you are not sure, start with a foundation inspection.
03Questions to ask
Ask how many piers are planned and why, how deep they are expected to go, and whether the warranty transfers if you sell. Compare the scope with our guide to warning signs in Comal County homes so you know which symptoms the plan is meant to fix.