Concrete Pier and Beam Foundation: The Pier Types Explained

The "piers" in a concrete pier and beam foundation are most often concrete or masonry — poured concrete, precast concrete, concrete masonry units (CMU, or block), brick masonry, or drilled-and-poured concrete piers, with steel and old wood posts rounding out the set. Which type you have, and which you actually need, is an engineering decision about your soil and load, not a one-size default. This page is about those vertical supports specifically: what each material is, how they differ, how they fail, and when to shim, replace, or reach for something deeper. For the whole system — the load path, the crawl space, the broad repair menu — start with our pier and beam pillar.

How the piers carry the house

In a pier and beam foundation the piers are vertical supports spaced roughly 4 to 8 feet on center, and they sit one link from the bottom of the load chain. Gravity travels downward in a strict sequence: subfloor → floor joists → beams (girders) → piers → footings → soil. Each pier collects the load delivered by the beam above it and transmits it to a footing — a concrete pad below — which spreads that point load over enough soil area to keep the bearing pressure within what the ground can carry.

Two facts about that arrangement decide almost everything else on this page.

• The footing has to bear below the local frost line. The International Residential Code §R403 requires footings to bear below the frost depth so seasonal freezing can't heave them. In most of Texas the frost depth is shallow (12 inches or less), but the principle is universal, and on expansive clay the more demanding constraint is depth below the moisture-active zone, not the frost line.
• Pier spacing is solved with the beam and the footing, together. Closer spacing means each beam spans less and each pier-and-footing carries less; wider spacing demands a deeper beam. The 4-to-8-foot range is a starting point, not a rule — the actual number falls out of the load and the soil's bearing capacity.

The piers are economical where loads are light, which is why concrete and masonry dominate residential pier and beam. Where loads are heavier, or where the bearing soil is deep, the engineering shifts toward steel or drilled piers that can carry more or reach further down. That trade — economy versus reach — is the through-line of the whole material comparison below.

The pier materials, compared

Residential pier and beam uses a handful of pier materials, and they are not interchangeable. The table below is the honest version: what each one is, where it earns its place, and what to watch for.

The pattern across the table is consistent. Concrete and masonry are the economical, standard choice for the lighter loads a pier and beam structure delivers. Steel and drilled piers cost more and exist for the cases concrete can't cover — heavier loads, or a bearing stratum that sits too deep for a short cast pier. And the two oldest materials, brick and wood, are mostly things you find rather than things you install today: they're common in historic homes, and they're the ones most likely to have deteriorated. The drilled-and-poured pier is the bridge between this page and the slab-underpinning world — it's also used as a foundation-repair method in its own right, which we cover under concrete pressed pilings and bell-bottom piers. The distinction worth holding onto: that page is about driving or drilling piers to underpin a foundation; this page is about the concrete piers that are the foundation of a pier and beam home.

True pier and beam vs block and base

Two homes can both be called "pier and beam" and be built differently at the perimeter — and the difference changes how the piers carry the house.

A true pier and beam foundation has a continuous, ground-penetrating concrete or masonry perimeter beam carrying the exterior walls. That perimeter beam doubles as the crawl-space stem wall, and freestanding piers appear only on the interior load-bearing lines. A block-and-base foundation has no continuous perimeter beam at all: the exterior walls rest on freestanding perimeter piers, exactly like the interior lines, with non-structural skirting closing the gap between them. From the street the two look identical. From inside the crawl space the tell is obvious — a continuous concrete wall around the perimeter means true pier and beam; individual columns with skirting between them mean block-and-base.

Why it matters here: in block-and-base, every exterior support is a freestanding pier, so the perimeter is only as sound as those individual piers and their footings. There's no continuous beam tying the perimeter together and redistributing load when one support settles. Both systems are repairable and both are inspectable, but block-and-base puts more of the structure's fate on discrete piers — which makes the pier material and footing size discussed above even more consequential. The pillar covers the disambiguation in full, including where "post-and-beam" fits.

How concrete and masonry piers fail

Concrete and masonry piers fail in a few well-understood ways, and they almost all trace back to either the soil moving or the materials aging.

• Clay pushes them out of plumb. Expansive clay swells when wet and shrinks when dry, and that movement is rarely even around a house. It heaves and drops the soil under different piers by different amounts, racking otherwise-sound piers out of vertical. An out-of-plumb pier loads eccentrically and fails prematurely. Our expansive clay soil guide covers the shrink-swell mechanism in detail.
• Old CMU and concrete crumble. Mortar joints in block piers degrade, brick spalls, and weathered concrete loses integrity — especially on a pier that has sat in a damp crawl space for decades. A crumbling pier stops carrying its share of the load, and the floor above it sags.
• Undersized footings sink. If the footing is too small for the load, or the soil beneath it was poorly prepared, the pier drives slowly into the ground under sustained weight. The pier itself can be perfect; the problem is below it, in the footing-and-soil interface. (When the failure is in the footing rather than the pier, see footing repair.)

The deepest version of the problem is the one homeowners most often miss. On expansive clay, the destructive shrink-swell action is concentrated in the near-surface active zone — commonly 8 to 15 feet deep in San Antonio — with stable, dimensionally quiet soil below it. A pier (or footing) that doesn't reach below that active zone is founded in the very soil that moves seasonally, so it will move again no matter how sound the masonry is. That single fact is why pier depth, pier type, and footing size are engineering decisions for the soil and load, not a contractor's default — the same logic that governs every deep-foundation method on this site.

Repairing or replacing concrete piers

Concrete-pier repair is staged and incremental, and the right intervention depends entirely on why the pier failed. The basic decision tree:

• Shim. Where a sound pier has simply lost contact with the beam as the soil settled, steel shims (more durable than the historic wood shims) take up the gap and restore the load path. This is the lightest, cheapest fix.
• Extend or replace. Where a pier has crumbled, gone badly out of plumb, or its footing has sunk, the pier is rebuilt or replaced on a corrected footing. Precast piers are common here because they set fast.
• Reach deeper. Where the failure is that the pier never reached stable bearing — the active-zone problem above — shimming or swapping the pier like-for-like just resets the clock. The engineer may instead specify a drilled-and-poured pier or a torque-set helical pier that seats below the moving soil. Helical piers, torqued to a verifiable capacity and governed by ICC-ES AC358, are the usual deep-bearing alternative when a shallow concrete pier won't hold.

All of this happens inside a larger re-leveling workflow — survey, shoring, synchronized incremental lift, support installation, then root-cause moisture and drainage work — which we cover step by step in the pier and beam repair guide. The one rule that should frame any pier work: a re-leveling scope is itemized by nature. A quote that reads as a per-pier, per-footing parts list is honest; a flat "level the house" number is a bet that usually favors the contractor.

There's a quieter failure mode worth naming alongside the structural ones: where a wood sill plate or a wood post rests on damp masonry without a capillary break, it is vulnerable to rot. Per the USDA Forest Products Laboratory's Wood Handbook, wood-decay fungi need sustained wood moisture above the fiber-saturation point (roughly 28 to 30%) to initiate decay, and ASHRAE Standard 160 ties surface mold growth to wood moisture sustained above about 16%. A masonry pier can be perfectly sound while the wood bearing on it quietly fails — which is why pier work and crawl-space moisture control belong in the same conversation.

FAQ Note

The FAQ below covers what San Antonio homeowners ask most about the piers in a pier and beam foundation — what they're made of, how far apart they sit, why concrete and block piers crumble, how deep they should go, and the concrete-versus-steel-versus-helical question. For a structured second opinion before any pier work, start with an engineer's report, and for the full system see the pier and beam pillar.

Get Matched With a Vetted San Antonio Pier and Beam Specialist

If a contractor has flagged a crumbling or settled concrete pier — or you want a PE-led read before committing to shim, replace, or underpin — we'll match you with a vetted San Antonio foundation specialist who can work to the engineer's design. The match is free, the quote is no-obligation, and we don't take a fee from you. We screen for sealed-engineer diagnosis, pier depths set below the local active zone, correctly sized footings, and a documented moisture-management plan alongside any structural work. If a quote proposes a like-for-like pier swap where the soil calls for deeper bearing, we'll tell you. That's the only way an editorial matching service should work.