How to Fix a Leak in Concrete

Cracked concrete walls that leak will only get worse over time.

Concrete is a strong material made with Portland cement, sand and water. Concrete will generally last several years without any maintenance issues. If the concrete was poured improperly, without any support inside the concrete, expansion or shrinkage may occur, causing cracks. This is common in areas with a high water content and cold winter weather. If a crack occurs, you should make repairs as soon as possible to prevent the crack from growing in size.

Things You'll Need

• Drop cloth
• Cold chisel
• Hammer
• Vacuum
• Gravel
• Cement
• Trowel
• Plastic
• Work gloves

Instructions

1. Place a drop cloth on the floor below the crack to catch any dust.

2. Set a cold chisel into the crack and strike the end with a sledgehammer to remove any jagged edges. The crack should be the same width from the bottom to the top.

3. Clean out the crack with a brush and a vacuum cleaner to remove any dust.

4. Mix a bucket of cement according to the instructions on the cement label.

5. Fill the hole halfway with gravel. This gives the concrete material to hold onto.

6. Put on your work gloves. Take a handful of cement in your gloved hands and push the cement into the crack. Remove your gloves once you are done packing the cement into the hole.

7. Push the concrete farther into the hole using a trowel, and then fill it as necessary, using the trowel to pick up the cement.

8. Smooth the concrete flush with the wall using the edge of the trowel.

9. Place a piece of plastic over the concrete patch to keep it from drying too quickly. Remove the plastic after 48 hours.

References

• Ask the Builder: Concrete Wall Repairs & Concrete Epoxy
• This Old House: How to Fix a Leaky Basement Wall