Permanent Foundation Crack Repair — Without Digging
Homeowners can breathe a sigh of relief: poured concrete foundation cracks can now be fixed permanently without expensive and disruptive exterior excavation. Low-pressure polyurethane or epoxy foam injection is a practical, cost-effective solution for typical shrinkage cracks in poured concrete walls.
With a 1% callback rate and 99% success rate, crack injection has become the accepted standard for foundation crack repair. Our process goes further than most contractors — we use a 3-step approach for maximum durability.
Our 3-Step Crack Injection Procedure
Stage 1 — Surface Seal with 2-Part Epoxy
Injection port packers are installed along the crack. A 2-part epoxy adhesive is used to seal the entire exposed crack surface, leaving only the port openings uncovered. The paste cures in 20–45 minutes and holds up under injection pressure.
Stage 2 — Polyurethane / Epoxy Foam Injection
Beginning at the lowest port, we inject urethane foam (the same material used on dams and pools) or epoxy, working upward port by port until material oozes from the next port — confirming the crack is filled to that level. Slow, constant pressure prevents blow-outs. We do NOT drill at 45° angles — this common shortcut forces drill dust into the crack, reducing bond strength.
Stage 3 — Flexible Caulk Swath (Optional)
After 24–48 hours of cure time, a 2–3" swath of our specialty 50%-flex caulk is applied over the repaired crack. It cures as hard as a gymnasium floor but has enough flexibility to accommodate future foundation movement. Ideal for older homes or foundations with seasonal settling.
Types of Foundation Cracks We Repair
- Vertical shrinkage cracks — most common in poured concrete walls, caused by concrete curing and settling
- Diagonal cracks — often from differential settlement or soil pressure
- Window corner cracks — stress concentration at window openings
- Horizontal cracks — may indicate lateral soil pressure (structural assessment recommended)
- Step cracks in block walls — mortar joint failures in block foundations
Important: Cracks wider than ¼", cracks that are actively growing, or cracks indicating foundation movement should be professionally assessed before repair. The significance of any foundation crack depends on its cause, size, shape, pattern, and location. If there is an underlying ongoing problem, it must be addressed too.
Block Wall Foundations
Block walls present unique challenges — hundreds of mortar joints, hollow cores that fill with water, and no single crack to inject. For block foundations, we typically recommend an interior French drain system rather than crack injection, as it handles water from all joints and from under the floor simultaneously. We can install exterior membranes for block walls requiring ultimate protection.
Why Crack Injection Works
Polyurethane urethane foam expands to fill micro-voids within the crack that you can't see. Once cured, it becomes waterproof and slightly flexible. Epoxy injection creates a structural bond that can actually be stronger than the surrounding concrete — used on bridges, parking structures, and dams worldwide.