On a slab foundation the house sits on concrete poured straight onto the ground, with nothing underneath to crawl into. Fixing one means working from the outside edge or through the floor, and in McKinney it also means an engineer and a $75 city permit.
What gets done to a slab
- Piers. Supports are installed under the slab, usually along the edge, to carry it on firmer soil and lift low areas. HomeGuide lists $1,000 to $1,600 per steel pier and $10,000 to $20,000 for an underpinning job (February 2026).
- Slab jacking. Material is pumped beneath a sunken section to raise it. The two guides we track disagree sharply here: Angi says $500 to $1,300, HomeGuide $4,500 to $9,000. Ask how much area is being lifted.
- Crack repair. Both guides list $250 to $800. On its own it seals a crack; it doesn't stop the movement that caused it.
More on how the guides compare is on our prices page.
What McKinney requires for slab work
The city's Foundation Repair Requirements sheet says its rules apply "to both slab-on-grade and pier & beam foundations alike." For a slab repair that means:
- An engineer's letter and drawings showing the affected areas, filed with the permit application.
- A note from the engineer on whether affected water, sewer or gas lines will need testing.
- A Final Engineer's Report uploaded to the permit once the work is done.
The plumbing note matters more on a slab than anywhere else, because supply and drain lines run under the concrete. Lifting a slab can stress them, and a leak under a slab can wet the clay and start the movement in the first place. Full detail: McKinney permit rules.
Newer homes and post-tensioned slabs
Much of McKinney was built after 1990, and many slabs of that era are post-tensioned, meaning steel tendons inside the concrete are tightened after it hardens. In a 2010 STRUCTURE magazine article, engineer Bryan Allred wrote that someone in the southwestern U.S. who had bought a house in the previous twenty years very likely lived on one. Concrete Network cautions against cutting or drilling such slabs, since a cut tendon is very hard to repair, and notes they are often stamped as post-tensioned. If yours is, make sure every contractor knows before they drill.
Before you sign
- Get the engineer's drawing and count the piers on it.
- Ask who arranges the plumbing tests and whether they're in the price.
- Ask for the permit number and a copy of the Final Engineer's Report.