Slab Foundation Repair in Tulsa, OK

Settled corners, cracked slabs, heave, and slab leak damage. Fixed from the outside in most cases.

A slab on grade foundation is one pour of concrete, four to six inches thick, with thicker edges called grade beams that go down a foot or two. Rebar runs through it in a grid. The house sits right on top. No crawl space, no access, no way to see what's happening underneath until it shows up in the walls.

That's the whole problem with slab repair in Tulsa. The clay under the slab swells in a wet spring and shrinks in an August drought, and the concrete has to go along with it. A slab is stiff. When the dirt under one corner drops away, the slab hangs over the gap until it cracks.

What it looks like in Tulsa slab houses

Every house built in the metro after about 1970 is on a slab. So is most of Lortondale, which went up in the 1950s on slabs before that was common. Here's where we see the most slab work and what it tends to look like.

• Lortondale and the 1950s ranches off 26th and Yale. Thin early slabs, often with the original copper plumbing under the floor. A slab leak that's been running for years softens the dirt and the corner nearest the bathroom drops. Tile cracks in a straight line across the hall.
• South Tulsa brick ranches, 1960s through 80s. Heavy brick veneer on a slab. The drought summers, 2011 being the worst, shrank the clay on the sunny south and west sides and the corner dropped. You get a stair step crack in the brick at that corner and a sticking door on the same end.
• Broken Arrow and Owasso subdivisions, 1990s to now. Built fast on lots that weren't always compacted well. Diagonal cracks start at the top corner of a window or door frame and angle toward the ceiling. A front door that binds every spring and swings free every fall.

The cause is nearly always one of four things. A perimeter section dries out and drops in a drought year. A plumbing leak washes out a void. The middle heaves up while the edges stay dry. Or a big tree within 15 feet drinks the moisture out from under one side.

How we fix it, step by step

1. Measure the floor. Zip level across every room, elevations written on a floor plan. This shows us the shape of the movement: one dropped corner, one dropped side, or a heaved middle. Each one gets a different fix.
2. Check for a slab leak. If the low spot is near a bathroom or kitchen, we want a plumber to pressure test the lines before we lift anything.
3. Lay out the piers. Piers go under the grade beam every 5 to 8 feet along the section that dropped. A single corner might take three or four. A full side takes six to ten.
4. Dig access pits. About 3 feet square at each pier spot, down to the bottom of the grade beam. Landscaping comes out and goes back in afterward.
5. Drive the piers. For a heavy brick house we use push piers, steel pipe driven hydraulically until it hits refusal, usually 18 to 30 feet down in Tulsa. For a lighter frame house we use helical piers, screwed in until the torque reading says we've hit bearing.
6. Lift. Hydraulic jacks on every pier, raised together a little at a time while someone inside watches the cracks and the doors. We stop when the house is stable and the doors swing, not when a laser says it's perfect.
7. Interior piers if needed. When the middle of the slab dropped, we either tunnel under from outside or cut through the floor. That's the invasive part, and we only do it when there's no other way.
8. Lock off, backfill, fix the water. Brackets get locked at the final height, pits get filled and tamped, and downspouts get extended away from the house so the same corner doesn't go again.

What it costs in Tulsa

Slab work is priced per pier. Per pier runs $1,400 to $2,800 depending on the pier type and how deep we have to go. Push piers are the lower end of that, helicals the upper. Interior piers through the floor run $2,200 to $3,500 each because of the concrete cutting and patching.

Whole jobs on Tulsa slab houses land in these ranges:

• One corner, two to four piers: $3,500 to $9,000.
• One or two sides, six to ten piers: $9,000 to $22,000. This is the most common slab job in South Tulsa, Broken Arrow, and Owasso.
• Most of the perimeter, 12 to 25 piers: $22,000 to $55,000. Usually a house that's been showing cracks for ten years, or a big custom home in Jenks or Bixby.

Permits in Tulsa run $150 to $400. The drywall, tile, and paint afterward are on you unless we agree otherwise.

How long it takes

Three to seven working days for most slab jobs. Push piers take two to four hours each in Tulsa clay. A ten pier job with lift and backfill is about a week. You stay in the house.

What can go wrong

• The lift opens new cracks. Pushing a corner back up two inches moves everything attached to it. Brick cracks often close. Drywall cracks sometimes open somewhere else. We lift slow with someone inside watching, and we'll tell you when stabilizing in place is smarter than a full lift.
• Plumbing under the slab breaks during the lift. Old copper and cast iron don't flex. On a 1950s Lortondale house we test before and after, and we budget for a plumber being involved.
• The unpiered section goes next. If we pier the south side because it dropped, and the north side drops in the next drought, that's a new job. We'll tell you up front which sides look like they're on borrowed time.

When slab piers are the wrong call

• The slab heaved, it didn't drop. Piers hold a slab up. They can't hold it down. A slab pushing up in the middle from wet clay needs water management, not steel. Drainage, downspouts, a root barrier, and fixing whatever leak is feeding it.
• It's a garage floor, driveway, or patio. Those aren't holding up the house. A settled garage slab or pool deck gets polyurethane concrete leveling, which is a one day job and a fraction of the price.
• There's an active slab leak. Plumber first. Then us. Sometimes once the leak is fixed and the dirt dries back out, the slab settles into a spot you can live with.
• The house is pier and beam. Happens more than you'd think with a slab addition on an old Brookside house. The addition gets perimeter piers. The main house gets crawl space work. Two different jobs.

FAQs

Read more: Foundation crack types and what they mean | Polyurethane foam slabjacking

Service areas: Broken Arrow | Owasso | South Tulsa

Related: Push piers | Concrete leveling | House leveling