Many basements, though they don't leak, are damp and uncomfortable. The first step is to fix any active leaks that exist. The next step is to determine the cause of the dampness and a proper solution.

The three most common causes are:

• water under the floor
• water build-up against the foundation walls
• condensation of humid air on the cool basement surfaces

Excessive dampness during wet rainy times of the year usually indicates that one of the first two causes is the problem. Excessive dampness in humid times and not corresponding with rainy wet times is often the third cause.

If you suspect any of these problems then you should try this simple test:

1. Tape a piece of aluminum foil to the floor or wall.
2. Tape completely around the edges making sure no air will be able to get behind the foil. Duct tape works well.
3. After a day or two inspect the surface of the foil. If there is water on it you probably have a condensation problem.
4. Peel off the tape and inspect the concrete underneath. If it's excessively damp or wet then you know that moisture is coming through it.

For problems under the floor, drainage and/or sealing maybe be necessary.Problems through the walls may require sealing the walls inside and grading or drainage work outside.Condensation problems commonly require a dehumidifier and anything you can do to cut down the amount of humid air that makes its way into the basement. Often the ground around a foundation will settle and allow water to pool near the walls. Check during rains to determine if this occurs, and if so soil should be brought into make the ground slope away from the foundation.If for some reason this isn't practical, it may be necessary to install a curtain drain system to collect and pipe the wateraway. Roof gutters and their unobstructed operation are important in keeping water away from the foundation. Make sure that the downspouts are extended away and don't dump water along the foundation. These can also be piped underground and away from the building.

Frequent observation during a rainstorm will help identify potential problems.Eastern Waterproofing Co., Inc. would be happy to provide you with references and a free written proposal for any of this type of work.