Exterior Peeling Paint and Ceiling/Wall Discoloration Problems:
Peeling exterior paint and discolored interior walls and ceilings (usually in the form of mold or mildew growth) are good indications that condensation is occurring inside wall cavities and attics. During winter, cold outside air collects in these areas and can cool attic, ceiling, wall cavity and interior wall surfaces to the point where condensation occurs. Adding insulation to these areas will warm these surfaces and thus help prevent condensation. Vapor retarders should be used in conjunction with the added insulation to prevent the migration of vapor into these areas from the interior of the home. Note: specially formulated vapor retarder paints are available on the market. They seem to be the least expensive and the easiest way to create a vapor retarder on the winter warm side of the ceiling or wall when insulation is added to these areas.
Sealing Interior Cracks and Holes:
When you add insulation, be sure to repair, caulk or weather-strip any holes or cracks in ceilings, walls and floors and along baseboards. These are prime areas for moisture migration to occur. Moisture vapor moves with air, and any cracks or holes that allow air to flow freely through them are potential trouble spots. Recent findings indicate that the sealing of these small, often overlooked areas can be a major factor in solving moisture problems occurring in attics and wall cavities.
Basement Wall Condensation Problems:
Adding insulation to basement walls has advantages similar to adding it to wall cavities and the ceiling: it eliminates cold surfaces where condensation can occur, and it cuts energy costs. Basement walls are often insulated by adding furring strips to the walls and installing rigid or batt insulation between the furring strips. If you use batt insulation, install a vapor retarder such as polyethylene film on the winter warm side of the batt insulation to prevent future moisture migration into it. To achieve a finished effect, place drywall over the vapor retarder. (Note: There is some question about using a second layer of polyethylene when batt insulation is used on basement walls.)
Rigid insulation is relatively impervious to water and moisture vapor damage. Therefore, it does not require the addition of a vapor retarder over or behind it when it is added to basement walls. As with batt insulation, drywall can and should be used over rigid insulation to provide a finished look and, in accordance with building codes, to provide a fire protective covering over the material that separates it from a habitable living space.
Keep in mind too, that if condensation is occurring in the basement during humid summer weather, windows and doors to the basement should be closed to help keep the humid air out. Open doors and windows when outside humidity levels are low to introduce dry air into the basement.
Toilet Tank and Water Pipe Surfaces:
Toilet tank surfaces are another common place for condensation to occur, particularly during warm, humid months. Warm toilet tank surfaces by either installing rigid waterproof insulation on the inside of the tank or adding a mixing valve to the cold water supply line. This introduces hot water into the tank water supply and can help warm the tank to a level that prevents condensation. Install tubular or wrap insulation around water pipes to prevent condensation there.
Seepage and Leakage:
Seepage or leakage problems commonly occur in the basement or crawl space in the early spring when snow and ice are melting and frost is beginning to leave the ground. They can also occur in the spring, summer and fall during and after heavy rains.
Seepage in a basement is the slow (non-pressurized) movement of groundwater through the basement walls. It may appear as a damp spot in an isolated area or in many spots. Leakage, on the other hand, is the fast (pressurized) movement of groundwater through the wall. In the case of leakage, the entry routes for the water are cracks or joints in the wall; with seepage, the water migrates through pores in the wall material.
Two conditions must exist for seepage or leakage to occur. First, the soil near the basement or foundation walls must be wet or saturated. Second, the basement or foundation wall must have a weak spot where water infiltration can occur.
Wet or saturated soil near basement walls can have several causes: improper disposal of roof water runoff, poor surface drainage away from the house, separation between the basement or foundation wall and the soil surrounding it (this crack acts like a funnel), window wells collecting rain water, lawn sprinklers located too close to the house, an inadequate below-ground footing drain system or a high water table.
Once the soil is wet or saturated, cracks, weak joints or pores in the masonry provide a route through the basement or foundation wall. Alleviate wet or saturated soil near the basement walls by minimizing or eliminating the moisture at its source. The installation, repair and maintenance of the gutter, downspouts and eaves-trough discharge system are necessary to minimize the ponding of roof water runoff close to the foundation. Eaves-trough discharges should terminate at least 3 feet away from the basement/foundation wall and gently slope away from the foundation at least 1 inch per foot of discharge run. An adequate ground slope away from the basement/foundation wall is needed to ensure that rainwater will be distributed away from the foundation. Generally, a slope of 6 inches in a 10-foot run of ground is adequate. All pockets or openings between the soil and the foundation should be filled with clean material that has good drainage characteristics, such as pea gravel and sandy soil.
Window well covers should be installed so that rain-water will not collect in the wells. Locate lawn sprinklers so they don't sprinkle the walls. A sump pump can be attached to the footing drain tile (a building contractor will be needed for this unless you're an experienced do-it-yourselfer) to drain excess groundwater away from the tile system and discharge it into a sump well set in the basement floor. In turn, the pump can then pump the waste water into the storm sewer system or to a ground area adjacent to the house. Choose a spot where the water will not damage the foundation or any adjoining property. Contact your local township or city building officials for specific guidelines on where to dispose of sump pump discharge.
Moisture / Condensation Problems - Summary:
Finding solutions to moisture problems, be they condensation or water problems, is often a difficult, time-consuming and expensive undertaking. The first step in any situation is to identify the source of the problem. This may not be easy because two and often more things may be working together to create the problem. Once you know the source, rethink the basics about condensation and/or water problems. What are the no-cost or low-cost solutions you can try first? Can the solution(s) attempted help you in other ways in addition to solving the moisture problem? The addition of storm windows, for example, can cut heating costs as well as help prevent fogging or icing of windows. In such a case, the cost of the solution may be well justified. In some cases, you may find you have to rely on outside help, such as contractors, engineers or architects. Do look into the backgrounds of these people to ensure that you are getting the best help available and that the solutions they offer will indeed solve the problems.