Follow that Leak! Finding the Moisture Source in the Basement

With wet basements being an issue in more than half the houses in the United States according to the American Society Of Home Inspectors, finding the  is a common concern for homeowners. It's no mystery why the basement is a moisture magnet. First of all, it's below ground, and thus exposed to water permeation from soil sources. Second, it's the lowest point in the house, so leaking water from any source above inevitably ends up in the basement. Here are some tips for finding the moisture source in the basement.


Warm humid air contacting cool concrete basement walls typically forms condensation. Tape a piece of aluminum foil tightly to the wall for a few days. If water droplets or dampness form on the outside of the foil, you have a condensation issue. Increasing basement ventilation or running a portable dehumidifier helps dry the air.

Rising Ground Water

Seepage upward through the basement floor occurs in areas with naturally high water tables. The hydrostatic pressure of rising ground water is strong enough to permeate concrete and penetrate small cracks. A sump pump installed in a basin excavated in the floor alleviates ground water pressure and automatically removes water.

Cracks In Walls

Basement wall cracks admitting soil moisture can be sealed by using commercially available crack repair kits, then applying a coat of basement wall sealant. However, sources of water soaking the soil should also be addressed. Make sure roof gutters are unobstructed, and do not overflow and cascade water to the ground adjacent to the wall. Also, landscaping next to the house should be graded to divert water away and prevent pooling next to the house.

Check The Plumbing

Water supply lines and drain pipes are typically routed through the basement and should be inspected for active leaks at joints and elsewhere. Because pinhole leaks in supply pipes may only leak intermittently, don't ignore signs like dry white mineral residue that indicates an on again/off again leak.

Ask the professionals at Rytech, Inc. for more about finding the moisture source in the basement.