Older raised homes · Re-blocking & re-leveling · Free inspection
Block and Base Foundation Repair in San Antonio.
Block and base foundation repair means re-leveling a house that stands on separate blocks and pads instead of a poured perimeter beam. The work is resetting those points: new blocks where old ones crushed or tilted, a solid base where the old one sank, steel shims to bring the beam back to height, and carpentry where a beam or sill has rotted. It is done from the crawl space by our pier and beam crew, and it usually costs far less than slab piering because nothing gets dug up around the house. The free inspection includes the crawl.
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The system
What a block and base foundation is.
A block and base house stands entirely on points. Each point is a stack: a base or pad on the soil, one or more concrete blocks on the base, and shims between the top block and the beam. The outside walls sit on the same kind of stacks as the middle of the house. That is the difference from true pier and beam, where a continuous concrete grade beam carries the perimeter and the piers only work under the middle. Skirting on a block and base home hides the crawl space, but it carries no weight.
To tell which one you have, look under the house from the access door or along the skirting. Daylight between separate blocks along the outside edge means block and base. A continuous concrete wall at the perimeter means pier and beam. Our guide to what a pier and beam foundation is has a labeled cutaway and a section on both.
How it fails
How a block and base house goes out of level.
Every point can move on its own, and on Central Texas clay they do. These are the failures we find most:
- Bases that sank. A pad set on expansive clay rides the soil up in wet seasons and down in dry ones, and the soft spots settle for good.
- Blocks that tilted or walked. A stack that leans is carrying the beam on an edge, and left long enough it kicks out.
- Shims that crushed or rotted. Old wood shims compress and decay, so the beam drops a little at a time.
- Beams and sills that rotted. Where water reaches the wood, a beam end or a sill plate goes soft and the floor sags there no matter how level the blocks are.
- Spans that are too long. Some older houses were built with too few points, and the beam bows between them. That is the bouncy floor.
Inside, it shows up as sloping floors, doors that stick or swing on their own, gaps at the baseboards and cracks over doorways. The full list is in the signs a pier and beam foundation needs repair, and it reads the same for block and base. If the floor gives underfoot, why floors get bouncy covers that one.
What the work is
What block and base repair involves.
Most houses need two or three of these, not all six. The inspection, including the crawl, sorts out which before anyone talks money.
Measure first
Floor elevations through the house before anything moves, so the plan starts from numbers rather than from where the floor feels wrong. You get the readings whether or not you hire us.
Reset the points
Jacks take the load off one point at a time. The old stack comes out, a solid base and new blocks go in, and steel shims set the beam at the right height. The floor comes back toward level in stages, re-checked as it goes.
Add points where the spans are long
New supports go in under the beam where it bows between the existing points. This is the usual fix for a bouncy floor.
Fix the wood
Rotted sills get replaced, and sagged or split beams get sistered or replaced. A level block under a rotten beam does not make a level floor.
Keep the ground under it dry
Grading, downspout routing and drainage so the soil under the points stops swinging. Skip this and the same points move again.
Deeper support where the soil will not hold
When the same points keep sinking, a pier that bears deeper goes in under the beam line instead of another block on the same soft spot.
Deeper support uses the same hybrid piers and steel piers we install on every other job.
Who does the work
Done by our pier and beam crew.
Block and base work goes to the same crew that handles our pier and beam foundation repair and mobile home leveling. They specialize in homes with a crawl space under them, so resetting a stack, sistering a beam and reading a floor elevation map from underneath is their everyday work. The rooms above stay in use while they work. If the crawl space is too low to get under, our crawler drone goes in for the inspection.
Costs
What block and base repair costs.
The price follows the number of points that have to be reset or added, the carpentry on beams and sills, how much room there is to work under the house, and any drainage work. Because the fix happens at the points that failed, with no digging around the outside, it usually lands well below a slab piering job. Typical ranges for crawl space work are in our guide to pier and beam foundation repair cost, and the written quote after the free inspection names the count.
If a bid for a house on blocks talks about driving piers around the whole perimeter like a slab, ask why. Most of these houses need their points reset and their wood fixed, not a perimeter pier line. A second opinion with a crawl is free.
Straight answers
Block and base questions, answered straight.
Related pages
Where to read more on this site.
Floors sloping in an older house on blocks?
Free inspection with a crawl, written elevation readings, and a straight answer about which points actually need work.
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Tell us what you're seeing.
We'll call to schedule, usually within one business day. Prefer to talk now? (210) 816-0034.
- 60–90 minutes on site, including the elevation survey
- Written summary whether or not repair is needed
- No-pressure pricing with firm numbers, no same-day-only discounts