Second, if condensation in the summer is the problem, do not ventilate the basement directly with warm, humid air. With moisture problems, the best approach is almost always to remove or control the source of the moisture, not to try to stop it at the last line of defense.įirst, the simplest and least costly techniques are to remove excessive internal moisture sources in the basement (humidifiers, cooking) and ventilate other sources (clothes dryer, bathroom). Then proceed in a logical order doing the next least costly technique with the most positive likely result. The best way to approach any building problem is to first do the things that are easy and low cost. Efflorescence, spalling of concrete or masonry.Īn overview of solutions to basement moisture problems.Staining and blistering of wall covering.Rot and decay of wood headers, joists, sill plates and columns.Condensation on cold walls and floor in summer.Saturated base of concrete block walls a ring of dampness.Then, a step-by-step process for addressing each problem is presented along with several detailed approaches to solving the problem. This page briefly describes moisture sources, moisture movement mechanisms and typical basement moisture problems. These problems can all be addressed and corrected if a systematic approach is used. Missing or nonfunctioning subsurface drainage systems are also found relatively frequently. Failure to slope the ground surface away from the foundation or lack of a good gutter and downspout system is common. In many cases, however, houses and basements can be structurally sound but are often not properly built to handle water drainage. Sometimes problems are traced to poor construction with cracking, settling foundations.
Moisture is transferred from the outside of the building to the basement interior by four mechanisms: Exterior humid air that enters the basement and condenses on cooler surfaces.