Sinking Foundation Repair Boerne, TX.

How we stop a sinking slab in Boerne

Why the ground under Boerne behaves differently

Boerne sits where the Edwards Plateau meets the Balcones Escarpment, and that seam shapes nearly every sinking-foundation case here. Instead of the deep, uniform Blackland clays that blanket the San Antonio basin to the east, a typical Boerne lot carries only a thin mantle of high-plasticity clay over fractured Edwards limestone. The practical problem isn't depth of clay, it's uneven bearing. Soil thickness changes sharply across the rock, so one corner of a house can rest squarely on stone while another spans a soft pocket of soil a few feet away.

The limestone itself is no guarantee of stability. Its joints and solution cavities channel rainwater in unpredictable directions, which means moisture content beneath a single slab can vary dramatically across a footprint of just thirty feet. Where clay collects in those low spots and seams, it still swells in the wet months and shrinks through the long dry stretch, pulling away from the edge beams it was supporting. The result is differential settlement: one area drops while the rest holds, loading the slab in bending it was never designed for.

Because the support is so localized, the first warning in Boerne is usually small and specific, a single sticking door, one racked window, or a corner that reads visibly low, long before the whole house looks off. Storm-water entering through limestone joints, perimeter soil drying out, and tree roots reaching laterally through shallow soil are the three drivers we see again and again behind that first low corner.

Signs a Boerne home is settling, and how to protect it

A few of these on their own can be cosmetic; together they usually mean the slab has lost support somewhere. Worth a survey if you're seeing them:

• A visibly low corner, or a floor that pitches noticeably toward one side of the house.
• Doors and windows racked out of square, sticking, dragging, or refusing to latch.
• Diagonal drywall cracks fanning from door and window corners; treat any that has opened past one-sixteenth of an inch in a year as a real signal, not a paint problem.
• Stair-step cracks in brick or block, or a gap opening between the slab edge and brick veneer.
• Keep the exterior grade falling at least six inches over the first ten feet, and run downspouts away underground rather than letting water pool against the rocky perimeter.
• During dry spells, a soaker line set twelve to eighteen inches off the foundation edge keeps the clay from contracting and separating from the beams.

Questions Boerne homeowners ask us