Slab Foundation Repair in McKinney
Pressed concrete piers $400 to $700 each, installed and warrantied
Late summer is when slab foundations in Collin County show their damage. The clay is at its driest from late July into September, after weeks of 100 degree days with almost no rain, and a lift reads truest once the October rains have put some moisture back in the ground. The soil under the exterior edge of the slab has dried and pulled away. The grade beam drops with it, and the brick above cracks in a stair-step pattern along the mortar joints.
A slab foundation is a single pour of concrete, four to six inches thick. Deeper grade beams run around the perimeter and under load-bearing walls. It is stiff but not rigid. When the soil under one side settles, the slab bends, and everything built on it bends with it.
Settlement versus heave
Settlement is the slab dropping where the soil has shrunk. Heave is the slab rising where soil has swelled, usually from a plumbing leak, a broken sprinkler line, or water pooling against the house. They look similar from inside. Doors stick and cracks open either way. The level survey tells them apart: settlement shows the edges low, heave shows an interior high spot.
The distinction matters because piers fix settlement and make heave worse. A heaved slab needs the water source fixed first. A large tree close to the house does the opposite, drying the clay under the nearest corner, and it goes on the same plan as the drainage.
The repair
- The inspector maps floor elevations and marks pier locations on a drawing, and an engineer seals it where your city or lender requires one.
- The crew digs a hole at each exterior pier location, about two feet square, down to the bottom of the grade beam.
- Precast concrete cylinders are pressed into the ground with a hydraulic ram, using the weight of the house, until they will not go further. A cap and shims go on top.
- Where the house is low, the slab is lifted on the new piers while a crew member watches the interior. The lift stops when doors swing and cracks close.
- Holes are backfilled and tamped. A hydrostatic plumbing test confirms the drain lines survived the lift.
Interior piers follow the same process through a small opening cut in the slab. Steel piers replace the concrete cylinders where the clay runs too deep for pressed concrete to reach stable soil.
Cost
Piers in McKinney run $400 to $700 each, installed, and the typical slab repair here lands in the range of $4,000 to $12,000. The number of piers depends on how much of the perimeter has moved, not on the size of the house. A house that has dropped at one corner may need six piers. One that has settled along two full sides may need twenty.
After the repair
Piers carry a written warranty that transfers to the next owner of the house, and we keep the pier drawing and the engineer's letter on file so a buyer's inspector can see exactly what was done and where. Keep the soil around the slab at an even moisture level through the dry months, keep gutters clear, and get any drainage problem fixed. Piers hold the house. They do not stop the soil from moving around the parts of the house that are not on piers.
Do not patch the cracks before the inspector has seen them; the pattern tells him which way the slab moved. (972) 645-5576 books slab inspections across Collin County.