DIY Block Basement Wall Waterproofing Using Foam Injection

Cracks in a basement wall will eventually allow moisture to seep into the basement. If left unattended, the cracks will grow larger and deteriorate to a point where you must call a professional to complete very expensive repairs. You can use polyurethane foam injection to repair vertical cracks that measure no more than 1/4-inch wide. If your cracks are horizontal along the mortar lines for your foundation or the cracks exceed 1/4-inch wide, you must consult a foundation specialist before moving on to ensure the safety of your foundation walls.

Things You'll Need

• Wire brush
• Small flat-head screwdriver
• Polyurethane foam
• Polyurethane foam catalyst
• Caulking gun
• Utility knife

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Instructions

1. • 1

     Scrub the walls around the crack with a wire bristle brush to remove loose debris from the wall. If you must, use a screwdriver to pick loose debris out of the cracks. Starting with a clean crack will yield the best results.

   • 2

     Blend the polyurethane and the activating agent together and then place the tube of polyurethane into your caulk gun.

   • 3

     Place the tip of the polyurethane bottle at the top of the crack and then squeeze the trigger. Fill the crack with polyurethane as you pull the tip down the full length of the crack. As the polyurethane exposes to the air, it turns to foam and fills in the crack.