In depth
Residential Foundation Repair in San Antonio: how the job actually runs
Residential foundation repair in San Antonio is three different trades wearing one name, because the metro has three generations of houses on two soils. The pier and beam homes built before about 1960 fail in the wood and the masonry. The conventional slabs of the 1960s through the 1980s fail on clay with a corroded drain underneath. The post-tension slabs of the 1990s onward tilt on fill in the north and on clay in the northeast. The evaluation starts by identifying which house you own, and the proposal is written for that house, not for a generic foundation.
Three eras, three failures
Pier and beam, before about 1960. Monte Vista, King William, Alamo Heights, Dignowity Hill, Tobin Hill, the historic cores of Seguin and New Braunfels, and the 1940s cottages of Harlandale. Wood beams on brick or concrete piers over a crawl space. Sills rot at the corners, beams sag between piers set too far apart, piers sink or crumble in wet clay, and old shims slip. The floor slopes toward the wet corner, the doors swing, and plaster cracks at the door frames. The fix is in the crawl space: reshimming, new piers on footings, sills and beams replaced, the crawl space dried. Details on the pier and beam page.
Conventional slab, 1960s to 1980s. Castle Hills, Hollywood Park, Leon Valley, Universal City, Highland Hills, the Southwest Side, Live Oak. Thin, lightly reinforced slabs poured on clay with cast iron drain lines in the trench beneath, and trees planted the same year as the house. The drain corrodes through and wets the clay under a kitchen or bath, heaving it; the trees dry the clay at the perimeter, dropping it. The slab reads high in the middle and low at the edges. The hydrostatic test comes first, the leak is repaired through a tunnel, the clay dries, and then pressed concrete pilings go on the perimeter if the survey still shows a drop. Details on the slab repair and leak repair pages.
Post-tension slab, 1990s onward. Alamo Ranch, Stone Oak, Helotes, Boerne and Garden Ridge on the limestone side; Schertz, Cibolo, Converse and the east side of New Braunfels on the clay side. Steel cables inside the concrete hold the slab together, so it tilts as a unit rather than cracking. On the rock side it settles toward the corner that sits on loose fill; on the clay side it tilts toward the dry edge each summer. The brick opens above the garage door, the doors on the low side stick, and the same failure repeats down a street of identical floor plans. Perimeter piers, steel where pilings refuse on rock, and drainage correction almost every time; interior piers only after the cables are located.
| Era | Where | Foundation | Usual failure | Usual fix |
|---|---|---|---|---|
| Before 1960 | Historic districts, Alamo Heights, Seguin core, south side cottages | Pier and beam | Rotted sills, sunk piers, sagging beams, wet crawl space | Reshim, new piers, sill replacement, moisture barrier |
| 1960s–1980s | Inside Loop 410, Universal City, Live Oak, south side | Conventional slab on clay | Leaking cast iron drain heaving the interior, trees dropping the corners | Hydrostatic test, tunnel and drain repair, pressed pilings on the perimeter |
| 1990s onward, north and west | Stone Oak, Helotes, Boerne, Alamo Ranch, Garden Ridge | Post-tension slab on limestone and fill | Fill settlement toward the low corner, builder drainage | Steel piers on the low side, drainage correction |
| 1990s onward, northeast and east | Schertz, Cibolo, Converse, New Braunfels east | Post-tension slab on deep clay | Seasonal tilt toward the dry edge, brick cracking | Pressed pilings on the moving side, watering plan, drainage |
What the evaluation does
It identifies the house first, because that says where to look: the crawl space, the drains, or the fill under the low corner. Then the elevation survey goes on a floor plan, every crack is mapped and dated, the water and the trees are read against the pattern, and on an older slab the drains are tested. The proposal that follows is for that house: reshimming and sills, pressed pilings, steel piers, a plumbing repair, drainage, or the honest answer that the house is stable and should be watched and watered. The inspection page walks through it.
Living around the work
Exterior piers are pressed from holes dug outside the grade beam, and nobody has to leave. The lift is one day, with someone inside checking doors and windows between stages. Interior piers mean a section of floor broken out, dug, pressed and patched, confined to that room and scheduled around the household. Pier and beam work happens in the crawl space. Tunneling for a plumbing leak is from outside. The noise is a hydraulic pump and shovels. The schedule in the proposal says which days involve what, and the second plumbing test and the final elevation record close the job out.
Paperwork that travels with the house
Texas does not license foundation repair contractors, so the file matters. The City of San Antonio requires a residential repair permit for structural foundation work inside the city limits, and Alamo Heights, Castle Hills, Schertz, Cibolo, New Braunfels, Boerne and the other suburbs run their own offices; the contractor pulls it. An independent Texas licensed engineer evaluates and writes the letter when the house, the lender, the buyer or the insurer calls for one, $400 to $900. The elevation survey before and after, the pier plan, the permit, the engineer’s letter and the warranty terms go in one file, because the Texas Property Code requires sellers to disclose known foundation repairs and the next buyer’s inspector will ask for all of it. How to weigh two proposals against each other is in how to choose a foundation repair company in San Antonio.
What it costs
A typical slab repair with 8 to 12 pressed concrete pilings runs $4,500 to $14,000; steel piers on the limestone side $1,000 to $1,800 each with fewer points. Pier and beam leveling and reshimming $1,500 to $5,000, with sill, beam or joist replacement $3,000 to $12,000. An under-slab drain repair after tunneling $2,000 to $8,000 plus the tunnel at $150 to $350 per linear foot. A drainage package from $1,000 for grading to $9,000 for a French drain. An engineer’s report $400 to $900. The full table and what moves the number are in the cost guide, and every number for your house goes in a written proposal after the evaluation.
While you wait
Find out what you own: a crawl space means pier and beam, a stamp at the garage slab edge means post-tension, and the year the house was built is on the county appraisal record. Photograph every crack with a coin and a date. Pull any previous foundation paperwork from the closing file. Note which doors stick and in which months, and where the downspouts end. Then send the form with the neighborhood, the foundation type and what the house is doing, and you will get an evaluation window and a proposal written for the house you actually have.
Last updated September 01, 2026
