Sinking Foundation Repair Leander, TX.

What a sinking slab actually looks like from inside

By the time a Leander homeowner calls us, the signs have usually been building for a season or two. Here's what tends to show up when a portion of the slab is losing its support:

• A corner or one whole side that reads visibly low, water pooling there after a shower, or a marble that rolls on its own
• Doors that latched fine last spring now dragging the jamb or refusing to close square
• Stair-step separations marching up the brick veneer, often widening near a downspout
• Drywall cracks fanning out from the upper corners of doorways and windows
• A gap opening between the top of an interior wall and the ceiling, or trim pulling away from the wall
• Hairline-to-open cracks crossing the garage floor or the slab itself

Why the fill under Leander homes behaves the way it does

Two decades of subdivision building pushed Leander neighborhoods onto land that was graded, regraded, and backfilled faster than careful geotechnical oversight could keep up. Crews moved large volumes of imported, clay-rich fill across parcels that were ranch or farmland not long before, and that fill rarely went down with the compaction and moisture control an engineer would specify. The native ground underneath isn't uniform either, it transitions from thin loam over limestone on the ridges to deeper, moisture-sensitive clay in the lower spots. The practical upshot is that two houses on the same street can sit on genuinely different bearing conditions.

The clay itself is the volatile ingredient. Central Texas clays commonly carry plasticity index values in the 40-to-60 range and higher, which means the soil swallows and releases a lot of water relative to its mass. A wet spring swells it; a hard summer drought shrinks it and pulls support out from under a section of the slab. Edges and corners usually drop first, because the perimeter grade beam overhangs the supported soil the farthest and because gutters, irrigation, and paving all distort the moisture right at the building line.

What makes Leander its own case is that mixed-fill variable. Where fill includes clay, caliche rubble, sandy pockets, and the occasional bit of construction debris layered without control, the denser zones hold load while the looser pockets keep compressing. That differential compression twists the slab and shows up as the uneven floors and cracked corners people recognize, and it's exactly why guessing at a pier layout from where the cracks happen to appear doesn't work.

Driving past the moving soil

The active zone, the depth where soil moisture actually swings with the seasons, runs roughly 8 to 15 feet below grade around here. Any repair that stops inside that band is still riding the wet and dry years. GroundLock drives galvanized steel piers hydraulically straight through the fill and through that active zone, bearing on the stable limestone or dense alluvial strata underneath, where surface weather no longer reaches.

Because the piers go in as connected sections under hydraulic pressure, we read each pier's capacity against the known weight of your house as it's installed. That means a pier is confirmed to be carrying load before we ever lift on it, a real engineering distinction from pressed-concrete cylinders that are stacked on the assumption of bearing and can drift inside the soil they never escaped.

Once the affected section is on steel and recovered toward its design elevation, the correction is held by the piers rather than the clay. That's also why we still look hard at water management: the piered area is locked, but unpiered ground keeps moving if drainage and grading let it. You can read more about how we handle that on our drainage work.

How a Leander repair runs start to finish

Questions Leander homeowners ask us