The words “Wet Basement” are all-too-familiar to many homeowners. It is said that more than 98% of all houses have had, or will have, basement leakage at some point, especially in Northeast Ohio.
The presence of efflorescence, a whitish mineral deposit on the interior of foundation walls, indicates moisture penetration. It should be noted that the severity of the problem, or whether the problem is active, is not indicated by the amount of efflorescence. Other clues are rusty nails in baseboards, rotted wood near floor level, rusted metal feet on appliances, mold and mildew, lifted floor tiles, storage on skids, peeling paint and the presence of dehumidifiers.
Poor surface drainage is one of the main causes of basement leaks. The ground should slope away from the house a rate of one inch per foot for at least the first six feet. As a preventative measure, seal where the driveway and sidewalk meet the foundation walls. If downspouts are ever suspected of being disconnected, broken or clogged below ground level, they should be redirected to discharge above grade at least six feet away from the house. Gutters should be kept clear of debris.
Localized low areas including basement stairwells, window wells, etc., may allow water to collect. Drains should be provided in the bottom of these. Where there are no drains, plastic dome covers over the window wells allow light into the basement while minimizing water and snow accumulation.
In the vast majority of cases, basement leakage is not significant from a structural point of view and can be controlled relatively inexpensively. However, the presence of foundation cracks, damaged perimeter drainage tiles, a high water table or underground streams may call for more extreme corrective measures. These measures are used when chronic flooding occurs.
Excavating, dampproofing and installing drainage tiles should be used as a last resort. Because excavating on the exterior is expensive ($10,000 +typically), an alternative is an interior drainage system. The cost of this approach is one-third to one-quarter the cost of exterior work. There are many cases where this proves satisfactory, although this must be judged on a case by case basis.