Foundation Inspection.

What the elevation survey actually records

An inspection here is a measurement, not a walk-through. Using a ZIPLEVEL PRO-2030 High Precision Altimeter, we map your floor to ±0.01 in. (1/64 in.) and read the shape of the slab. These are the data points that end up in your report:

• A contour map of the floor plane, high points, low points, and the inflection lines where the slab transitions from one to the other.
• The magnitude of differential across the slab, and over what span it occurs: two inches dropped across 40 feet is a very different story than two inches across 12 feet.
• Crack geometry, width, and direction, diagonal stair-step cracking through brick mortar usually means differential settlement, while uniform-width vertical cracks are often just concrete shrinkage.
• Which way the interior doors bind: top-corner toward the center points to a center-lift pattern; bottom toward the perimeter points to perimeter settlement.
• Perimeter drainage and grading, whether water sheds away from the slab or pools against it, and any irrigation or trees creating localized moisture differences.
• A plain read on whether you need work at all. Plenty of inspections end in a monitoring plan, not a repair quote.

Why the same inspection can't be done two ways in Central Texas

Central Texas sits on a geological seam. The Balcones Escarpment splits the region into two foundation worlds: east of it lies the Blackland Prairie, where Houston Black clays carry plasticity indices that routinely run 40 to 60 or higher and swell and shrink with the seasons. West of it, in the Hill Country, thin residual soils, sometimes only six inches deep, drape over fractured Edwards limestone.

Those are not minor differences. A slab cracking over high-plasticity prairie clay is responding to soil that changes volume; the same cracks over shallow rock near the escarpment may be telling a completely different story. A competent inspector has to know which side of that line your house sits on before drawing a single conclusion, which is exactly why a one-size template misses what is actually moving your foundation.

On the clay side, the survey has to account for the active zone, the depth to which seasonal moisture swings change the soil's volume. Across this region that zone commonly runs six to ten feet below grade, and drought-recharge cycles can push it deeper. A slab poured in a wet year sits on swollen clay; when the site later dries and that clay pulls away, the slab loses support and a corner drops. Rehydrate it after a drought and you get the opposite, upheaval.

The job of the inspection: cosmetic or structural

Cracks alarm everyone, but their engineering meaning varies wildly. The core purpose of a structural inspection is to separate cosmetic movement from structural distress, both produce cracks and sticking doors, yet only one warrants piers. We read crack patterns against the elevation data so the conclusion rests on geometry and measured deflection rather than wherever a crack happened to show up.

Drainage and vegetation are part of the findings, not an afterthought. Large shallow-rooted trees within 10 to 15 feet of the slab, downspouts dumping at the foundation, and grade that tilts water toward the house will keep driving movement even after a repair. Where it matters, the report points to drainage correction or erosion control as part of a lasting fix.

When work is genuinely warranted, the survey drives the layout. The contour shows where the perimeter or interior needs support, roughly how many piers are indicated, and where they go. GroundLock then drives galvanized steel piers hydraulically to refusal on load-bearing strata below the active zone, the difference between a foundation that's stabilized and one that rides the next drought. You can see how that translates into a full foundation repair scope.

How a GroundLock inspection goes

Questions Central Texas homeowners ask us