How to Stop a Basement Wall Leak

Installing proper drainage when laying a foundation prevents most water-caused cracking.

A basement wall leak is a cause for concern. Even the smallest leak can lead to mildew and mold problems -- and leaks always grow bigger. A leak caused by a foundation crack must be fixed from the outside. An inside patch will eventually be forced out of the way by water pressure coming in from the outside. In addition, if the water drainage is poor around the foundation, the problems will likely reoccur if the drainage is not corrected.

Things You'll Need

• Shovels
• Tarps
• Rented sandblaster
• Exterior crack repair kit
• Chisel and hammer
• Water-resistant coating
• Paint brush
• Gravel
• PVC drainage pipe

Instructions

1. Dig a trench around as much of the exterior of the home as you can, exposing the foundation. A backhoe makes the task easier but may damage nearby landscaping.

2. Sandblast the foundation wall to remove all dirt, paint and previous sealant.

3. Locate the cracks in the exterior wall, using the interior cracks as a guideline. Use a commercial crack-sealing product to fix the crack. The crack may need to be widened along the course of it with a chisel and hammer to give the sealant access to deep inside it.

4. Inject the sealant along the length using a hypodermic needle. Ensure that the entire crack is coated on the inside. Missing even a 1/4-inch length ensures that the crack will likely reopen.

5. Seal the widened part of the crack with the sealant compound that comes with the sealing product. Use a fingertip or Popsicle stick to work it into the crack, forcing out all air bubbles. Trowel it smooth afterwards.

6. Paint the entire foundation wall with a commercial water-resistant sealant and let dry.

7. Install a French drainage system if there is no drain. Extend the trench 6 feet into the lowest part of your yard and slope it so that it is slightly lower than the trench alongside the house. At the end of the trench, dig a 3-foot deep hole that is at least 2 feet or more wide. This is your well that allows the water to drain away from your house.

8. Lay down 6 inches of gravel along the bottom of the entire trench and fill the end hole to the level of the trench.

9. Place 6-inch diameter of perforated PVC drainage pipes along the length of the trench, with the perforated side down.

10. Add another 2 feet of gravel to the trench and then fill the rest up with the soil that was removed earlier. Have the soil along the foundation a few inches higher than the soil along the rest of the yard so that the water drains from the foundation outward.

Tips & Warnings

• This is a major task to do yourself. Waterproofing companies are available to give you an estimate but they are in business to make money and can add expensive services that may not be needed.

References

• The Money Pit; Basement Waterproofing Tips; Tom Kraeutler; February 2009
• Danny Lipford; Fixing Foundation Drainage Problems with a French Drain; Julie Day
• I Can Fix Up My Home: Install a French Drain System for Drainage