Foundation Repair in Kirby, TX

Kirby sits at about 689 feet on the flat blackland east of downtown San Antonio, and the ground here is deep, expansive clay rather than the shallow rock of the Hill Country. That clay is the whole story of foundation damage in this town. When it soaks up water it swells, and in a Central Texas drought it shrinks and pulls away from the foundation. A slab poured on that ground rises and falls a little every year, and over enough cycles the movement concentrates at the weakest points and the concrete cracks.

Three local factors make it worse. First, the age of the housing. Much of Kirby was built out in the 1950s, 60s, and 70s, when slabs were thinner and less reinforced than what code requires today, so those foundations have less strength to resist the clay pushing beneath them. Second, the drainage pattern. Kirby drains through Rosillo Creek, which runs through the city on its way to Salado Creek in southeastern Bexar County, and the lots closest to that drainage stay wetter on one side than the other. Uneven moisture is exactly what makes expansive clay lift one part of a slab while the dry side drops. Third, the flat ground itself. On level lots with older gutters and short downspouts, roof water tends to pond right at the foundation edge after a storm instead of running off, feeding the swell-and-shrink cycle at the perimeter.

The repair that works in this soil is a deep one. We press steel piers down through the active clay until they reach load-bearing strata that the weather cannot reach, then lift the slab back toward its original elevation and fix the drainage that caused the problem.