How to Fill a Crack in a Basement Wall

Basement walls will usually crack over time from stress and water damage.

Basement walls are usually constructed of concrete to make them as strong and durable as possible. However, the basement is also a common location for water leaks and drastic temperature changes that can result in wall cracks from the frequent expansion and contraction. Repairing a basement wall is usually not difficult once the underlying cause of the crack has been dealt with. Filling a crack in a basement wall can be done quickly with the right materials.

Things You'll Need

• Caulk gun
• Polyurethane foam

Instructions

1. Look for any signs of leaking around the crack, such as moisture or water staining. If the crack is caused by a leak, the leak should be repaired before you fill the crack. Otherwise, the crack reappear or a new one will occur right next to it.

2. Load a caulk gun with a container of polyurethane foam. Hold the nozzle of the caulk gun up against the crack and lightly press the trigger.

3. Run the nozzle of the caulk gun down the length of the crack as the polyurethane is being distributed, filling the crack completely. The liquid polyurethane will start to foam once it interacts with moisture in the crack. This causes the foam to expand and bond with the concrete.

4. Allow the polyurethane to dry. It will form a tight, permanent seal to the concrete along the entire length of the crack.

References

• Concrete Network: Concrete Crack Repair
• Radon Seal: About Cracks in Foundation Walls
• InspectAPedia: How to Repair Foundation Cracks Using Polyurethane Foam Injection