House Leveling Cibolo, TX.

Telltale signs a Cibolo slab has dropped a corner

The calls we get most around Cibolo start with one of these, and they almost always trace back to the floodplain clay shrinking and swelling under the slab:

• Stair-step cracks climbing through the exterior brick or block, usually starting at a window corner
• Interior doors that drag the jamb or won't latch, and windows that stick when they used to glide
• Drywall tears fanning diagonally from the corners of door and window frames
• Floors you can feel slope as you walk a room, or that bounce near the low side
• Gaps opening where trim meets the ceiling, or where the wall pulls away from a countertop
• Hairline-to-wide cracks across the slab or at the garage-floor joint

Why the ground under Cibolo won't sit still

Cibolo sits on one of the more demanding stretches of the San Antonio, Austin corridor. The Cibolo Creek floodplain laid down high-plasticity expansive clay, soil closely related to the Houston Black series that dominates the Blackland Prairie, and it ranks among the most active shrink-swell ground in Central Texas. Plasticity indices here commonly run above 40, and that clay can change volume by several percent across a single wet-winter, dry-August cycle.

What that means underfoot is a slab that rides the seasons instead of staying planted. Dark prairie clay holds water like a sponge, then gives it back in a drought, so a foundation can move measurably in one year. Tree roots and a leaking supply or sewer line concentrate the drying in one spot, which is why so much of the damage shows up at a single corner rather than spreading evenly across the house.

There's a second wrinkle near the creek: alluvial fill and natural deposits can leave the soil profile uneven from one side of a lot to the other. Two homes on the same street, or two corners of the same slab, can behave very differently, which is why we measure every job rather than assume.

Why we drive steel piers past the active zone

The active zone, the depth where surface moisture still changes the soil's volume, frequently reaches 10 to 15 feet in floodplain clay like Cibolo's. Above that line the ground is in constant motion; below it the clay holds a stable moisture equilibrium year-round. The whole game is getting your home's load past that line.

Pressed-concrete piers, the cheaper option, are usually set only 8 to 10 feet deep, so they stop inside the moving soil. When the surrounding clay swells or shrinks, the pier rides along with it and the slab settles all over again. GroundLock's galvanized steel piers are driven hydraulically past the active zone entirely, advancing through whatever depth of clay is present until they hit load-bearing strata, bedrock, dense limestone, or a competent caliche layer, that can hold a proof load. That resistance-based stopping point is the difference between a permanent repair and a cosmetic one.

Lasting results pair the lift with water control. A finished grade that falls about six inches over the first ten feet carries storm water away before it saturates the perimeter beam, so we'll flag where drainage correction or erosion control is worth doing, recommended only where it actually protects the slab.

How a Cibolo leveling job runs

Cibolo house leveling questions