Why pier and beam matters in San Antonio
The city’s census numbers say San Antonio is older than its suburbs: 43% of its homes pre-date 1980, against 17% in Schertz and 5% in Helotes. A lot of that older stock is raised-floor. There’s no dataset that counts foundation types by city, so look at the house: vents or an access panel in the skirting mean a crawl space.
The City’s Office of Historic Preservation notes that many historic houses in San Antonio have pier and beam foundations. In some neighborhoods you’ll also see limestone foundations; the guidelines say many can be restored rather than replaced.
How a pier and beam house is built
The floor sits on joists, the joists on beams, the beams on piers, with a crawl space underneath. Piers can be cedar, concrete blocks, or poured concrete. Shims fill the gap between a pier and a beam. ASCE’s Texas Section says shims on pier caps may be hardwood or steel.
Call to schedule an inspection
What goes wrong
- Piers settle or tilt. The FPA says improper drainage or ponding under a block-and-base house can let blocks move, settle, or tilt.
- Spacing. Sagging can come from blocks placed too far apart under the beams.
- Rot and insects. Damp wood loses strength.
- Clay movement. On San Antonio’s east side the soil under the piers still swells and shrinks.
- Plumbing leaks. The FPA notes that leaking lines can cause the pier to move.
The repairs
ASCE’s Texas Section lists these: shimming, framing repair, new or added supports, and restored void space. In plainer terms:
| Repair | What it fixes | Published figure |
|---|---|---|
| Re-shimming | Low spots on sound piers | $1,600 average (Angi) |
| Added piers | Spans that sag between supports | $800–$4,000 per pier (Angi) |
| Beam replacement | Rotted or cracked beams | $400–$1,200 per beam (Angi) |
| Whole-job range | Combined work | $1,500–$15,000 (HomeGuide) |
Call to schedule an inspection
Re-shim or rebuild?
Re-shimming is the cheapest option and works when the piers are sound and the movement is small. Rebuild when piers are rotting, tilting out of plumb or sitting in mud. A good contractor shows you which piers they’d shim, which they’d replace and why, on a drawing.
Keep the crawl space dry
Most pier and beam trouble starts with water. ASCE’s Texas Section lists these under-floor moisture measures: cross ventilation, under-floor drainage, ground clearance for beams and joists, and treated lumber. The Office of Historic Preservation’s guidelines add: keep downspouts directed away and soil sloped away, and keep the foundation vented.
Call to schedule an inspection
Permits and paperwork
San Antonio’s bulletin says some repairs carry extra requirements: skirting, ventilation, subfloor access and drainage. If skirting is removed during the repair, that’s part of the permit and the city’s final inspection. If your house is in a historic district, call the Office of Historic Preservation before work begins; their guidelines treat shoring, replacement skirting and vents.
What to expect afterward
Floors are closer to level but not perfect; ASCE’s Texas Section is blunt that perfection is not attainable by remedial measures. Keep the engineer’s letter, the readings, the permit and the warranty terms.