Pier and beam foundation repair

Raised foundations in the Metroplex are largely a question of vintage. One DFW contractor describes pier and beam as "common in DFW homes built before 1965" and slab on grade as "standard in DFW construction after 1970," naming Oak Cliff, the M-Streets and the original parts of Plano and McKinney as mostly pier-and-beam areas (Stratum Foundation Repair); another lists Lake Highlands, Lakewood and parts of University Park, built between the 1940s and 1970s (Level Home Foundation Repair). Neither publishes a percentage, and no one does for the existing stock. As a labelled proxy for how rare new raised construction has become, 8 percent of new single-family houses completed in the South Census region in 2025 were built over a crawl space, against 88 percent slab or other (U.S. Census Bureau).

The structure you are paying to fix

A raised floor is a stack: interior piers or pads, girders (often called beams) spanning between them, floor joists crossing the girders, subfloor on top. Each connection point is shimmed. Repair work usually means entering the crawl space, placing bottle jacks or screw jacks under a girder, taking load off in small increments across several points at once, and then either re-shimming the existing pier caps or building new pads. Rotten shims get replaced with steel or treated material. Where a girder has cupped, split at a splice, or lost bearing, a section is sistered or replaced outright. Sagging joists are sistered alongside or swapped one at a time. None of this is fast: the load has to be moved gradually, or the plaster and tile above pay for it.

Interior piers in North Texas usually bear on shallow pads sitting directly in Blackland Prairie clay, and that is where the trouble starts. The clay is high in montmorillonite, so it "swells when they are wet and shrink and crack when they dry" (USDA Soil Survey of Dallas County), and Houston Black — the dominant series across the eastern Metroplex — develops cracks "1.3 to 10 cm (1/2 to 4 in) wide at 30 cm (12 in) depths during dry periods" (USDA Official Series Description). A shallow interior pad riding on that clay drops in a dry summer and comes back up after a wet winter. That is why raised houses here often need re-shimming every decade or two rather than one permanent fix, and why an honest crew will tell you that shimming buys years, not permanence.

Shim, or underpin

The important question in any bid is whether the work adds depth or only adds height. Re-shimming and adjusting existing piers restores elevation without changing what the piers bear on. Underpinning — driving new piles below the active moisture zone — changes the support itself, and where a perimeter beam is being underpinned the Foundation Performance Association's spacing maximums apply: 8 feet on center for a one-story structure, 7 feet for a 1½-story or two-story with brick on the first story only, 6 feet for a two-story brick structure (FPA-SC-08-1). Underpinning is oversold on raised houses. If the girders and joists are sound and the piers have simply settled unevenly, new piles are an expensive answer to a shimming problem. Conversely, if the same corner has been shimmed three times in fifteen years, more shims are the wrong answer.

Published costs

DFW pier-and-beam work is published at $3,500 to $20,000 and up (Level Home Foundation Repair), with Texas-wide guides putting most jobs at $5,000–$15,000, sill beam replacement at $4,000–$12,000, localized beam or joist repair at $1,500–$6,000 (roughly $1,800–$4,500 per 12 linear feet), releveling without new underpinning at $2,000–$6,000, and extensive framing rebuilds at $15,000–$30,000 and up (Foundation Compass). National data prices individual joist replacement at $350–$1,000 each (HomeGuide). Crawl space clearance drives labor cost more than square footage does: an 18-inch crawl and a 36-inch crawl are different jobs at the same house size.

Before you sign

Ask for photographs of every member the bid says is damaged, an elevation reading taken at named locations rather than a general "the back is low," and a written statement of which piers are being re-shimmed versus rebuilt. Ask whether the crawl space will be left with its vapor barrier reinstalled. Then check the permit: Grand Prairie defines foundation repair to include "leveling, installation and/or replacement of piers, footings, or any modification/alteration of any part of the flooring system," requires a permit and a stamped engineer's letter and plans, and processes applications in about 5–10 business days (City of Grand Prairie); Denton requires a permit for all foundation repairs with an engineer-sealed letter and plan, at a $100 fee (City of Denton). A bid that treats the permit as optional is telling you something.