Most basement water problems appear as drips or spurts coming from a wall or as seepage coming up through a crack in the floor or between the wall and the floor. However, the source of basement water is frequently surface water that pools against the exterior of basement walls. The water flows down the wall until it finds a crack or hole in the wall through which it can enter the basement. The way to prevent such basement water problems is to be sure that the ground near the basement wall slopes down away from the house. Ideally, it should slope down 10 to 15 feet from the house and have a drop of at least 6 inches. However, even a sloped area of 3 feet will usually do the job.

Another common source of basement water problems is improperly working gutters. Check gutters to make sure that they are not clogged with leaves and twigs which cause them to overflow and prevent rain from going down the spout. Downspout extenders can be a problem if they are not long enough to direct water several feet away from the house. Adding an extension onto the downspout can correct this problem. Splash blocks may not handle the volume of water and are often too short to direct and carry water away.

Improperly installed basement windows can also be a source of water problems. If the window is near grade or below grade, a window well should be installed. The well should extend a foot below the bottom of the window frame or have a drain system, such as rock extending to the footing drain so that the water that accumulates in the well can drain before it reaches the level of the window and enters the basement.

The above sources of basement water problems should be explored before considering adding any type of waterproofing, coating, or drain tiles to an existing home.

If you have had water in your basement, you will want to dry the basement out as quickly as possible. However, if the soil outside is saturated with water and the basement is pumped out too fast, the pressure from the exterior water may collapse or damage the wall. Once you have mopped, vacuumed, or pumped the water from the basement, you need to remove the residual moisture that is left in the concrete, wood, and other materials. Removing as much of the wet material from the basement as possible will reduce the amount of moisture that has to be removed by a dehumidifier or ventilation. A dehumidifier is one option. It will operate most effectively if you close the basement up as tightly as possible so that the equipment is not trying to dry the entire house. If you have openable windows and can mount fans in them, that is another solution particularly on dry, sunny days. A third possibility is to run the blower of a warm air furnace with the vents in the basement open. This should add enough warm air from upstairs to the basement to speed the drying. The moisture still needs to be removed with a dehumidifier or by outdoor air exchange, or you will have a warm, damp basement—good conditions for mold growth.

If possible, remove carpeting and dry outside. If the carpeting was installed using tack strips, it may be possible to remove it, have it cleaned, and reinstalled.

If you can't remove the carpeting, remove as much moisture as possible using a wet vacuum, then use fans to circulate air over and preferably under the carpet. The carpet must be dried within 12 to 24 hours, or it will become infested with mold and need to be discarded. Carpet and padding that are wet due to overland flooding likely need to be discarded because the water is polluted with a variety of chemical and biological materials.