Thirty years of slab on grade subdivisions south of 71st Street, brick veneer over wood frame, and the deepest smectite clay in the metro underneath.
South Tulsa is everything from 71st Street down to the Creek Turnpike and past it to 121st, between Riverside and Memorial. It's the newest big piece of the city. The subdivisions off 81st, 91st, and 101st went in from the 1970s through the 2000s, a few hundred houses at a time, and nearly all of them went up the same way. Slab on grade, brick veneer, a two car garage, a sprinkler system, and a couple of trees from the nursery planted ten feet from the foundation.
Slab on grade, all of it. The 1970s and 80s houses sit on conventional reinforced slabs with grade beams 18 to 24 inches deep. From the late 1990s on, a lot of builders switched to post tensioned slabs, which hold together better but still ride the clay. Either way, the whole house sits inside the top two feet of soil, the layer that swells in April and shrinks in August.
The dirt under South Tulsa is some of the heaviest smectite clay in Tulsa County. Jenks and Bixby get the same stuff. Subdivision grading made it worse in places. Cut and fill lots, where the builder scraped one side and piled the dirt on the other, settle unevenly for decades.
Drought, mostly. The perimeter of a slab dries faster than the middle. In a summer like 2011 or 2022, the clay under the edge shrinks and the corners drop while the center stays put. The brick opens a stair step crack at the corner. A door to the garage binds at the top. Then a wet spring like 2015 swells everything back, unevenly, and the cracks that closed over winter open wider.
The damage shows up a year or two after the dry summer. Spring 2012 was the busiest season this part of town has seen, and spring 2023 wasn't far behind.
The other big one is slab leaks. The 1970s and 80s houses have cast iron drains under the slab, and a lot of 80s and 90s houses have copper supply lines in the concrete. Both fail. A leak washes out the clay, opens a void, and the slab drops into it. You can't see it. The first sign is a water bill or a warm spot on the tile.
The trees that came with the house are the problem now. A pin oak planted in 1985 ten feet off the slab is 40 feet tall and pulling hundreds of gallons out of the clay every week in July. The side of the house facing it settles first.
Sprinklers are the South Tulsa special. Heads aimed at the foundation keep one side wet and swelling all summer while the side without coverage bakes. That differential is what breaks slabs. Pulling the heads back five feet fixes more foundations here than piers do.
Remodels are lighter than in Midtown, but a kitchen with a slab cut for an island sink is common, and those patches are rarely compacted underneath.
Push piers at the perimeter. Steel piers get driven down through the clay to stable soil, brackets go under the grade beam, and we lift the settled corner back to level. That takes the corner out of the swell and shrink cycle for good. Most South Tulsa jobs run six to ten piers along one or two sides.
For a slab that's dropped less than two inches with no leak underneath, polyurethane foam can lift it without piers. Faster and cheaper, but it doesn't fix the soil.
Drainage goes with every job. Downspouts carried six feet out, grading sloped away, sprinklers pulled back. Without that, the piers hold and the rest of the slab keeps moving.
Written quote after a free inspection.
Age isn't the issue. The clay is. A 1990s slab with 24 inch grade beams sits entirely in the active layer. Add 25 years of tree growth, a sprinkler system against the foundation, and a drought like 2022, and it moves.
Builds from the late 1990s on often are. Look for a stamped warning on the slab edge or in the garage. It changes where we can drill and how we lift, so we check before we quote. Piers still work. Foam still works.
Yes, and in South Tulsa it's one of the top causes we see. Heads spraying the foundation keep one side wet and swelling while the other side bakes. Pull the heads back five feet or switch that zone to drip.
A slab leak shows up as a water bill jump, a warm or damp spot on the floor, or one corner dropping fast while the rest stays put. Settlement from clay is slower and usually shows at the perimeter after a dry summer. A plumber with leak detection gear can tell you which.
Yes. We measure the slab, check the perimeter and drainage, and write you a quote. No charge.
Nearby neighborhoods: Lortondale | Brookside
Related service: Slab foundation repair and piers
Related reading: Why settling is worse after drought years | How long foundation repair takes in Tulsa
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