Foundation Repair Guide: Types of Damage, Methods & Costs

Foundation Types

Slab-on-grade: A concrete slab poured directly on the ground. Common in warmer climates and newer construction. No basement or crawl space below. Foundation issues manifest as slab cracking, heaving, or settling.

Crawl space: A short foundation wall (2–4 feet) creating an accessible space between the ground and the first floor. Common in moderate climates. Foundation issues include wall cracking, bowing, and moisture damage.

Basement: Full-height foundation walls (7–9 feet) creating a usable below-grade space. Common in northern climates. Foundation issues include wall cracking, bowing, water intrusion, and floor slab cracking.

Pier and beam: The house rests on concrete or stone piers connected by beams. Common in older homes. Foundation issues include pier settling, beam rot, and uneven floors.

Warning Signs

Foundation problems often announce themselves before they become severe. Watch for: cracks in interior drywall (especially at door and window corners), doors and windows that stick or won't close properly, uneven or sloping floors, cracks in exterior brick or siding, gaps between walls and ceiling or floor, visible cracks in the foundation itself, and water intrusion in the basement.

Crack Types

Vertical cracks: Common and usually caused by concrete shrinkage during curing. Typically cosmetic (not structural) unless wider than 1/4 inch or growing. Seal with epoxy or polyurethane injection to prevent water intrusion.

Horizontal cracks: More concerning. Indicate lateral pressure from soil pushing against the wall (hydrostatic pressure). Can lead to wall failure if not addressed. Requires structural evaluation.

Diagonal (stair-step) cracks: In block or brick foundations, these follow the mortar joints in a stair-step pattern. Indicate differential settling (one part of the foundation settling more than another). Requires evaluation and possible underpinning.

Repair Methods

Crack Injection

For non-structural cracks in poured concrete walls. Epoxy injection (structural bond, restores wall strength) or polyurethane injection (flexible, waterproof, accommodates minor movement). DIY kits available ($30–$100) or professional injection ($300–$800 per crack).

Carbon Fiber Straps

For bowed or leaning basement walls (up to 2 inches of inward bow). Carbon fiber straps are epoxied vertically to the wall, stabilizing it and preventing further movement. Minimally invasive, no excavation. $400–$800 per strap (typically 4–8 straps per wall).

Steel Wall Anchors

For bowed walls beyond the range of carbon fiber. Steel plates are attached to the interior wall and connected by steel rods to anchor plates buried in the yard. Tightening the rods over time can straighten the wall. $500–$1,000 per anchor (typically 3–6 per wall).

Helical Piers (Underpinning)

For settling foundations. Steel helical piers are screwed deep into stable soil beneath the foundation, then connected to brackets that lift and stabilize the foundation. Each pier supports 5,000–15,000 lbs. $1,000–$3,000 per pier (typically 6–15 piers per home).

Push Piers

Similar to helical piers but driven (pushed) rather than screwed into the ground. Used when loads are heavier or soil conditions favor driven piers. $1,000–$3,000 per pier.

Mudjacking / Foam Leveling

For settled concrete slabs (driveways, garage floors, basement floors, sidewalks). Mudjacking pumps a cement slurry under the slab to lift it. Polyurethane foam injection (polyjacking) is lighter and more precise. Mudjacking: $3–$6/sq ft. Polyjacking: $5–$25/sq ft.

Costs

Crack injection: $300–$800 per crack.

Carbon fiber straps (one wall): $2,000–$6,000.

Wall anchors (one wall): $2,500–$6,000.

Helical/push piers (whole house): $8,000–$25,000.

Mudjacking: $500–$2,000 per area.

Complete foundation repair: $5,000–$40,000+ depending on severity.