How to Seal a Leak in Concrete

Cracks lead to leaks which lead to countless problems.

Leaks in concrete can be a major headache to any homeowner. Cracks in concrete walls and foundations can often lead to harmful leaks which can cause expensive water damage. Water damage from such leaks can lead to thousands of dollars in repairs. If, however, you have the proper tools and instructions and can seal a concrete crack yourself, you can save a lot of money -- both immediately and in the long run.

Things You'll Need

• Wire brush
• Damp cloth
• Pointing trowel
• Work gloves
• Hammer
• Chisel
• Water-based epoxy
• Epoxy resin
• Fiberglass cloth
• Safety goggles
• Safety mask
• Garden hose
• Plastic sheet

Instructions

1. Wet the leaky area of the concrete with a garden hose for several minutes. This will help the old concrete bond to the patch you will be applying and will make obvious any loose chips of concrete.

2. Clean the crack with a wire brush, brushing away any loose bits of concrete. Use a hammer and chisel to lightly chip away any other loose bits that the wire brush cannot remove.

3. Wipe down the leaky crack with a damp cloth. Make sure the crack has been cleared of any concrete dust and loosened bits.

4. Apply water-based epoxy to the crack with a pointing trowel. Coat the leak completely, without missing even the tiniest spot. Apply three coats. Let it cure.

5. Take a piece of fiberglass cloth and put it over the seal you have just created with the water-based epoxy. Apply epoxy resin over the fiberglass cloth to bond it to the seal. Use three coats of epoxy resin.

6. Cover the repaired leak with a plastic sheet. Keep it covered for five days.

Tips & Warnings

• If you miss even the tiniest hole, the leak will continue to be a problem. Make sure you have completely sealed the crack that has caused the leak.

• Wear work gloves, safety goggles and a safety mask at all times while working with any form of epoxy.

References

• Leaking Basement Concrete Foundation Wall: Step by Step Instructions to Permanently Repair That Wet/Dry Concrete Crack
• Progressive Epoxy Polymers, Inc.: Epoxies etc. for Basement Sealing -- Commercial Grade Epoxy Resin Systems -- Concrete Leak Stop -- Leaky Basements
• Aubuchon Hardware: How to Repair Concrete