If your basement smells wet or damp, but you don't see any obvious sign of a leak, you may be left wondering if you have a humid basement or a hidden water leak. Water leaks and high humidity are both very common basement issues because the basement is located underground with limited air flow. There is a very simple test you can perform in your basement to determine if you have a leak or if you just have high humidity.
Things You Will Need
Cut 8 or more pieces of aluminum foil into 12 to 15 inch pieces.
Use a waterproof tape to tape the pieces of aluminum foil to your basement walls. Tape the foil sheets down on all four sides. Tape the aluminum foil at various heights on all walls of your basement. One near the ceiling, one near the floor and so on. Waterproof tape is available at hardware stores and home improvement stores.
Leave the aluminum foil undisturbed for at least 5 to 7 days.
Look at the aluminum foil. If the side facing out is wet or has collected any moisture, the dampness in your basement is caused by a high level of humidity in the air. If the side of the aluminum foil facing the wall is wet the dampness is caused by water leaking through your basement walls from outside.
For high humidity levels in a basement use a dehumidifier to remove the humidity from the air.
For water leaks, seek the source of the leak. It can be caused by roof leaks, clogged gutters and downspouts, cracks in the foundation and many other reasons.
A damp basement is not a healthy environment. Dampness and water will lead to mold and mildew growth. This is why it is important to determine the source of the dampness and then correct the problem.