How to Install Foam Sealant in Concrete Walls

Cracks are common in older homes made of masonry and basements made of concrete. These cracks let in not only cold air, but also water, which can lead to damaged floors and mold. While the best way to fix masonry or concrete is with mortar and masonry mix, you can use a spray foam sealant to help seal off small cracks or holes.

Chisel
Spray foam sealant
Utility knife

Instructions

- 1
  Remove the debris from cracks or holes with a chisel. Scrape out any loose concrete. Even small particles will interfere with the seal of the foam once it is sprayed.
- 2
  Shake the can of foam sealant thoroughly for at least one to two minutes. Failing to properly mix the sealant will result in a runny mess.
- 3
  Hold the can upside down, and aim the nozzle into the crack before you spray. Do not spray with the can in the upright position.
- 4
  Release the foam into the crack or hole. Use an even amount of pressure on the can's trigger. Do not overspray. Fill the hole or crack, and then let the foam set until it is hard to the touch -- typically eight to 10 hours, depending on the humidity in the room.
- 5
  Trim any foam that has expanded beyond the patched area with a utility knife. Use the knife to shave the excess off until the patch is level with the rest of the wall.

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