How to Repair Cracks in a Cement Block Basement Wall

Cracks in cement block basement walls could indicate larger problems.

The basement of your house is under constant pressure from the structure above and from the earth to the sides and below it. The most common type of basement wall crack is a crack that forms in the mortar around the cement blocks. Cement blocks and mortared joints in a basement wall can crack over time because of stress, settling, freezing water, expansion, contraction and from an impact. All basement cement cracks should be looked at by a professional before patching. Patch only cracks that are diagnosed as cosmetic and nonthreatening. Wear leather gloves and eye protection while working on this repair.

Things You'll Need

• Wire brush
• Shop vacuum
• Cold chisel
• Hammer
• Hydraulic cement
• Small bucket
• Jointing tool or pointing trowel

Instructions

1. Scrub the crack out with a wire brush. Remove all loose pieces and debris with a shop vacuum.

2. Create a stable base by chiseling out the crack with a cold chisel and hammer. Remove loose pieces and debris with a shop vacuum.

3. Following the manufacturer's directions mix hydraulic cement with water in a small bucket. Fill the chiseled out crack with the hydraulic cement mixture using a jointing tool or a pointing trowel.

4. Fill the crack completely until the damaged area is flush with the existing area.

Tips & Warnings

• Some foundation cracks can lead to foundation failure and should be taken seriously.

References

• "Ultimate Guide To Home Repair And Improvement; Creative Homeowner; 2006
• InspectAPedia foundation wall problems