A wet basement leads to many problems such as mold and deterioration of the poured concrete or concrete block. Dampness or water in the basement is caused by condensation from interior moisture, seepage from the outside or a combination of the two. Once you determine the source, use the Basement Waterproofing technique that will solve the problem of dampness or water in the basement.
The easiest way to determine the source of basement water problems is to inspect the basement walls. Inspect each wall for moisture or drips. Check the seam between the walls and the floor around the perimeter of the basement for damp areas and obvious water spots.
If the cause of the dampness is not obvious, such as drips, runs, pooled water or obvious dampness, the moisture may be seeping into the basement slowly; there may be high moisture in the basement, or both. Place a 2 foot by 2 foot piece of aluminum foil or heavy plastic on a wall where there is suspected problems. Tape the edges securely with a waterproof tape such as surgical tape purchased in a drugstore. In 24 to 48 hours, check the outside of the foil or plastic. If there are water beads on the outside, condensation, or high humidity, is the likely source of the problem. Remove the foil or plastic and inspect the other side for moisture. If it is damp or there are beads of water on the side next to the wall, water is seeping into the basement from the outside. If both sides are wet, there is both condensation and seepage. However, the seepage may be the cause of the condensation.
Control condensation by sealing areas where moisture enters the basement. Apply caulk or foam sealant around basement windows and doors as well as pipes and wires that go through walls to the outside. Insulate water pipes to prevent them from sweating. If there is a dryer in the basement, check that it is properly vented to the outside, and seal the area between the vent pipe and wall with caulk or foam sealant.
Control seepage by making sure gutters are clean and not overflowing when it is raining, which adds moisture to the soil surrounding the house. Make sure downspouts are clear and extend at least 10 feet from the house. Grade the soil around the house so it slopes a minimum of 6 inches for the first 10 feet of soil next to the house. If there are gardens close to the foundation, plan watering around rain so that the soil is damp, but not saturated. Slope gardens so that heavy rains run off away from the house.