Basements are typically the area of a structure most at risk for water damage because they are located below grade and surrounded by soil. Soil releases water it has absorbed during rain or when snow melts, and the water can end up in the basement through leaks or cracks. Water can even migrate through solid concrete walls via capillary action, which is a phenomenon whereby liquid spontaneously rises in a narrow space, such as a thin tube, or via porous materials. Wet basements can cause problems that include peeling paint, toxic mold contamination, building rot, foundation collapse, and termite damage. Even interior air quality can be affected if naturally occurring gasses released by the soil are being transmitted into the basement. Prevent water entry by diverting it away from the foundation.
Preventing water from entering the basement by ensuring it is diverted away from the foundation is of primary concern. Poor roof drainage and surface runoff due to gutter defects and improper site grading may be the most common causes of wet basements. Addressing these issues will go a long way toward ensuring that water does not penetrate the basement. Roof and surface water must be controlled to maintain a dry basement. This means keeping gutters cleaned out and aligned, extending downspouts, installing splashblocks, and building up the grade so that roof and surface water are diverted from the house. There should be one downspout every 30 feet. The major cause of gutter failure is clogging due to debris. There are two types of gutters, hanging and built-in. Built-in are usually made of wood and are difficult to maintain. Hanging gutters are usually metal or vinyl. They should be cleared of debris and inspected for sagging to prevent water from backing up behind the gutters and entering the home. The best time to check gutters is during a heavy rainstorm. Downspouts should be directed away from the foundation of the home.
Basement Dampness – Basement dampness is frequently noted in houses and the conditions which cause it are usually capable of determination by an experienced home inspector. Often, however, in houses which are being offered for sale, the visible signs on the interior of a basement which would indicate a past or present water problem are concealed. For example, an area may be painted over, or basement storage may be piled against a wall where a problem has occurred. If there has been a dry period before the time of the inspection signs of past water penetration may not be visible. In such cases, the building analyst may not be able to detect the signs of basement dampness or water penetration. Most dampness in basements, garages and crawlspaces are caused by the following: Downspouts which exit at the foundation causing seepage through cracks in walls, doorways and window wells. The ground near the basement is flat or slopes toward the house allowing water to pool against the foundation walls. No gutters or downspouts (or defective ones). Rain falls off the roof and erodes the soil near the foundation.
Condensation on Cool Surfaces. The crawlspace or basement is at or below the ground water level. Check drywells which tend to clog up. To correct these situations you should do the following: Make sure gutters and downspouts are not clogged or leaking. If possible, extend the downspouts further away from the foundation. Keep window wells clear of debris and make sure they are the proper height. Cover them with plastic covers to shed excess water. Run a dehumidifier in the basement during the damp season. Regrade the ground at the exterior of the home to a slope of 3 inches per foot for approximately 3 feet (for a 15 degree angle or 1 inch per foot). Do not allow the soil to touch or cover the house siding. If these steps alleviate the problem, then you should coat the interior of the basement walls with waterproof paint. Clean the walls, seal all joints, cracks and holes with waterproof caulk and paint the area. The paint does not prevent water penetration, but helps control dampness.
Expensive solutions to basement dampness problems are frequently offered, and it is possible to spend many thousands of dollars for such unsatisfactory solutions as a system for pumping out water that has already entered the basement or the area around or under it. Another solution sometimes offered is the pumping of chemical preparations into the ground around the house. This has been found not to be of value. If leaks or seepage is occurring in the basement’s interior, water and moisture are most likely entering through small cracks or holes. The cracks or holes could be the result of several things. Poor workmanship during the original build may be making itself apparent in the form of cracks or holes. Water pressure from the outside may be building up, forcing water through walls. The house may have settled, causing cracks in the floor or walls. Repairing all cracks and small holes will help prevent leaks and floods.