How the Foundation Is Built
A pier-and-beam foundation raises the structure above the ground on a grid of supports. Understanding the components makes the repair scope much easier to follow.
Piers. Vertical supports carrying the load to the ground. Older homes often have masonry or concrete block piers on simple footings; newer or repaired sections may have poured concrete footers.
Footings. What the piers bear on. Undersized or absent footings are one of the most common findings in older homes, because standards at the time of construction were different.
Girders or beams. Horizontal wood members spanning between piers, carrying the floor structure above.
Subfloor joists. Smaller members spanning between girders, carrying the subfloor and everything on it.
Sill plate. The member the wall framing bears on, sitting atop the girders.
Crawlspace. The accessible space beneath the floor, and the reason this foundation type is repairable in ways a slab is not.
Our pier-and-beam repair page covers the full service. This guide focuses on the work itself.
Which Homes Have This Foundation
Across the San Antonio area, pier-and-beam construction dominates housing built before roughly 1960. Alamo Heights, Monte Vista, the older parts of Universal City and Schertz, historic New Braunfels and Seguin, and scattered properties throughout the older central neighbourhoods.
A meaningful number of homes have both: an original raised structure with a later slab-on-grade addition. The junction between the two is often where movement shows first, because the two foundation types respond differently to the same conditions.
What Goes Wrong
Two categories, and they are genuinely different.
Support problems. A pier settles, a footing was never adequate, or ground movement shifts a support out of position. The structure above loses its bearing at that point and the floor drops.
Material problems. Wood in a damp crawlspace decays. Rot at girder bearing ends, termite damage to joists, and fungal decay in the sill plate all reduce load capacity regardless of whether the ground has moved at all.
The second category is what distinguishes pier-and-beam from slab work. A slab foundation problem is almost always a ground problem. A pier-and-beam problem may be a ground problem, a wood problem, or both, and an assessment has to look for each.
Typical Repair Scope
Beam shimming. Where a girder sits low over a pier that is itself stable, shims restore contact and correct the local elevation. The lightest correction available and appropriate when the support underneath has not moved.
Sistering joists. Fastening a new joist alongside a weakened one to restore capacity without removing the original. The standard response to rot at a joist end, termite damage, splitting, or over-notching for plumbing.
Girder replacement. Where damage runs through the section rather than sitting at the surface. Load is taken by screw jacks and temporary cribbing, the old member comes out, and new material goes in.
Pier and footing work. Where a pier has settled or its footing was inadequate, new support is built: a concrete footer poured to depth with a new pier above, or a rebuilt pad-and-block assembly.
Crawlspace moisture management. Vapor barrier over exposed soil, attention to ventilation, and correction of drainage channelling water under the house.
Re-leveling. Adjusting support across the structure to recover elevation toward level, in controlled increments.
Our guide on how beams, joists, and piers are repaired covers the mechanics of each.
Access Considerations
Everything happens in the crawlspace, which has practical implications.
Clearance. Workable clearance is generally around eighteen inches or more, though the practical figure depends on where the work sits relative to the access point. Tight crawlspaces slow every task and that shows in the schedule and the cost.
The access point. Sometimes an existing hatch or vent opening is adequate; sometimes it needs enlarging.
What is stored down there. Belongings, and sometimes pets, need relocating before work starts.
Services. Plumbing and ductwork running through the crawlspace may need temporary disconnection.
All of this is established at the evaluation rather than discovered on the crew’s first morning.
The advantage worth appreciating
Every structural member is reachable. On a slab, addressing something beneath the middle of the house means tunnelling or cutting the floor. On a pier-and-beam home, someone crawls to it. That accessibility is why these foundations are generally less expensive to correct and why they can be adjusted repeatedly over a long life.
What the Household Experiences
Considerably less than most people expect. The work happens under the floor rather than in the living space. There is noise, crew members coming and going through the crawl access, and occasional periods where a section is being actively jacked.
Most households stay in place throughout. Where a substantial re-level is planned, expect some relief cracking in plaster or sheetrock and some doors needing adjustment afterwards, which is discussed before work begins rather than explained afterwards.