Foundation repair across the Houston metro
The clay under Houston is not uniform. The south and west of the metro sit on Beaumont-formation clay that opens two-inch cracks in a dry summer; the north and west sit on loamier Lissie and Willis ground that moves less, but not zero; the river bottoms of Fort Bend and Brazoria are something else again. The repair scope follows the soil, so this page starts with the soil. Pick your area below for what we actually see there.
Three kinds of dirt, three kinds of repair
Most of the city sits on the Beaumont formation, Pleistocene river and floodplain deposits that dried out and compacted when the water table dropped during the last ice age. The clay in it carries montmorillonite, which is the mineral that swells. North and west, the older Lissie and Willis formations put loamier soil on top. Which one you own decides how many piers you need.
South, southeast and southwest
Lake Charles and Beaumont clays: 45 to 60 percent clay by weight, surface cracks half an inch to two inches wide when dry, open 60 to 90 days in a typical year. A southwest Houston site tested in the 2011 drought ran a plasticity index of 36 to 74, which is high to very high swell. Pier counts and depths run highest here, and the drainage work matters most.
North and northwest
Aldine, Hockley and Wockley soils: sandy loam and loam over clayey subsoil, on the Lissie and Willis formations. A northwest Houston site measured a plasticity index of 9 to 23, low to moderate. The same study's warning applies here, though: clays with low to moderate swell potential still swell hard when they have been dried out, and the 2011 drought dried them to 10 feet.
River bottoms and the coast
Brazos and San Bernard alluvium in Fort Bend and Brazoria, layered sand and clay toward Galveston Bay. Profiles change within a block, so the elevation survey and a look at the borings matter more than the map. Fort Bend's prairie clay is the type location for the Lake Charles series; its river valley is not.
The active zone, the trees, and the water table that left
How deep the seasons reach
Houston clay wets and dries to a depth engineers call the active zone: about 6 feet, give or take 2, from seasons alone in southeast Houston, 8 to 10 feet at four sites measured before the 2011 drought, and roughly 2 feet deeper after it. A mature oak changes the arithmetic. Large oaks can pull more than 55 gallons a day in a dry summer, and under one southeast Houston building the active zone reached about 28 feet.
A floor that breathes
A study of 453 Southeast Texas slab foundations, surveyed 1998 to 2002, found the average slab about 2¼ inches out of level at the start of the growing season and about 3¾ inches by late summer, then recovering over winter as the soil rehydrated. That is why we record the month of your survey: a floor read in August is not the same floor read in February.
The water table moved
In the late 1970s it was common to hit groundwater 5 to 15 feet down. Slabs, paving and graded lots blocked recharge, and landscape trees drew the rest; 15 to 25 feet is now typical. Less water within reach means the clay dries deeper and the trees dig further for it, under your slab if that is where the moisture is.
What 2011 taught the city
Seventeen inches of rain in twelve months, about a third of normal, and a record 109°F August. Water mains at the typical 4-foot depth sat inside the active zone, and the city went from about 12 main breaks a day to more than 120. Houses on the same clay did the same thing more quietly.
The soil map is not the diagnosis
University of Houston engineers evaluated forty structures on one Beaumont-clay site in 1977 and found only a weak link between computed swell potential and actual distress. Buildings founded entirely below the seasonal zone were damaged about as often as those at the surface; rainfall swings during and right after construction predicted trouble better than the soil numbers did. Fifty years later the lesson holds: two houses on the same street can need six piers and twenty-six. The floor elevation survey is how we find out which one is yours.
Texas engineers already wrote the rules
The Texas Section of the American Society of Civil Engineers publishes the residential foundation guideline Houston engineers evaluate against: deflection measured against the same L/360 limit the code uses for a floor beam, tilt flagged past 1 percent, cheap fixes first (gutters, a 5 percent grade for the first 10 feet, tree management), a sealed plan from an engineer of record, a plumbing test after any lift, and a compliance letter at the end. Our house leveling and cost pages walk through what that means for your job.
One thing piers do not fix: regional subsidence. Pumping groundwater compacted the clay in the aquifers under the east side, up to nine feet near the Buffalo Bayou and San Jacinto confluence, and that compaction is permanent. The Harris-Galveston Subsidence District has regulated it since 1975. It lowers whole neighborhoods together; the shrink-swell above is what tilts one house. Figures on this page come from University of Houston CIGMAT papers, the ASCE Texas Section guidelines, NRCS soil series descriptions, the USGS and the subsidence district, and the Texas State Historical Association county entries.
Services
Slab Foundation Repair
Conventional and post-tension slab cracking, leveling, and engineered pier repair.
Pier and Beam Repair
Releveling, wood pier replacement, and crawl space moisture control for pre-1960s Houston homes.
Foundation Drainage
French drains and regrading that stop the water problem behind repeat foundation movement.
Common requests
The questions homeowners actually call with, answered with Houston numbers rather than national averages.
Areas with local guides
West University Place
Harris County
Beaumont Formation clay, Lake Charles series (Vertisol) · 1920s-1940s original stock; ~50% rebuilt post-1992 on slab
77005
Oak Forest
Harris County
Beaumont Formation clay, Vertisol clay (high-plasticity, shrink-swell) · 1947-1965 original post-WWII construction; accelerating teardown-rebuild infill since ~2010
77018 · 77092
Also serving
We cover these areas today. Local guides are being written as we build up survey data for each one — call for anything here.
- Katy
- Fulshear
- Sugar Land
- Missouri City
- Richmond
- Rosenberg
- Cypress
- Tomball
- Magnolia
- Spring
- The Woodlands
- Conroe
- Humble
- Kingwood
- Atascocita
- Pearland
- Friendswood
- League City
- Webster
- Clear Lake
- Baytown
- Deer Park
- Pasadena
- The Heights
- Montrose
- River Oaks
- Bellaire
- Memorial
- Meyerland
- Garden Oaks
- EaDo
- Midtown
- Museum District
- Medical Center
- Galleria / Uptown
- Energy Corridor
- Westchase
- Champions
- Klein