Foundation Crack Repair

Not every foundation crack is a structural problem. Poured concrete shrinks as it cures, and thin vertical cracks are common. But some cracks are a warning sign that the foundation is moving, and any crack can let water, radon or insects into the house. A foundation contractor can tell you which kind you have.

Which cracks should you worry about?

• Cracks wider than about 1/4 inch
• Horizontal cracks in basement walls
• Stair-step cracks in block or brick
• Cracks that are wider at one end than the other
• Cracks that keep growing or reopen after being patched
• Cracks where one side is offset from the other

Typical crack repair costs

Repair	Typical range*
Epoxy or polyurethane crack injection	$300 – $800 per crack
Sealing multiple wall cracks	$1,000 – $3,000
Slab crack repair	$300 – $1,000
Crack stitching / reinforcement	$500 – $2,000

*General US ranges for orientation only, not quotes. Local contractors set their own prices after inspecting your home.

Epoxy vs. polyurethane

Epoxy injection bonds the two sides of a crack and restores some strength, which suits stable structural cracks in poured walls. Polyurethane foam expands to fill a crack and stays flexible, which suits cracks that leak water. Neither fixes the cause of movement: if the crack is caused by settlement or soil pressure, the contractor will recommend piers or wall stabilization first.

A simple way to track a crack is to mark its ends with a pencil and date and photograph it every few months. If it grows, call a contractor.