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Basement Dampness
A common complaint among home owners is the musty smell, dampness, and water damage that are signs of a wet basement or crawl space. About 60 percent of all houses in this country suffer from some form of below ground wetness. Block foundations are especially vulnerable, with an 80 to 90 percent chance of leakage within the first 20 years. Even in homes without basements or crawl spaces, excessive moisture can adversely affect ground level floors.

If you've been putting off dealing with your basement or crawl space because you think it's going to be too expensive or too complex to fix, you should know that simple remedies may offer relief from the problem. Once you learn all you can about water control, you can get to work on routine maintenance and care that may make the difference between damp feet and a dry, comfortable room. Start by trying these solutions:

1. Slope the adjacent ground away from the house at a descent of approximately 1/2" to 1" inch per linear foot. Poor grading or improper backfill are the most common causes of seepage and leakage.

2. Gutters and downspouts (leaders) play an important role in diverting water away from foundation walls. Clean them each spring and fall, or as often as needed, particularly if large trees overhang the roof. Make sure the gutters drain and slope properly towards the downspouts. Maintain and repair them periodically, as needed.

3. Test underground drain pipes with water from a garden hose to help determine whether or not they are functioning properly. Have clogged or broken underground drainage pipes repaired, or abandon them and install splash blocks, downspout elbows with above ground piping or downspout extensions. Continue piping and extensions 8 feet from the foundation if the home has a basement: 4 feet if it has only a crawl space.

4. Stop water entry through basement windows by maintaining window wells that are at least 4 inches above a positive grade away from the house. Clean the window wells periodically, as needed. Inexpensive plastic domes can often help keep window wells from filling up with leaves and debris which can hold water.

5. Remove sunken flower beds close to the foundation walls as they may hold too much water. Flower beds can be established close to the house if the basic grade is positive, i.e., away from the house, and the soil is not soft.

6. Keep exterior cellar stairwells, drains, and doors clear of leaves and debris that can hold water.

7. Adjust automatic sprinkler times to reduce the amount of watering. Sprinklers near the house should be checked to ensure that water is not being sprayed against the foundation, unless you live in an area of expansive clay soils, where such sprinkling may be necessary to maintain a consistent soil moisture level. Be sure they do not spray into crawl space vents.

8. Be sure that patios, driveways, and walkways slope away from foundation walls, l/4" per linear foot. Seal cracks between foundation walls and these surfaces with a flexible material such as caulk.

1. Seal with a flexible material, any minor cracks in foundation walls and joints against seepage.

2. If the basement or crawl space has a dirt floor, cover it with a sheet of 6 ml. polyethylene to help reduce ground moisture and humidity.

3. Prevent sweating or dripping from condensation by wrapping cold water pipes, well pressure tanks, and air conditioning ducts with insulation.

4. Use a de-humidifier when humidity is high.

5. Vent any below-grade level bathrooms or laundry areas to the outside to control moisture accumulation.

In order to develop a positive slope away from the house it should be done as follows:

1. Remove any soft soils or porous materials, such as top soil, mulch and wood chips, from low areas around the house until you get down to the more dense clay soils. If there is no clay, 8" to 12" should be sufficient depth.

2. Bring in clay, a dense brown/orange soil, and fill the area close to the house. Develop a positive slope away from the house at approximately 1/2" to 1" per linear foot, i.e., the soil should be at least 3" higher at the wall than it would be 6' away from the house. Be sure to tamp the new clay properly so that it will shed water away from the house. Two sources of clay are new building sites and landscaping contractors.

Note: In areas where clay is not available, use the soil that will compact best. You may wish to contact the Department of Agriculture's local County Extension Agent to learn more about the soils in your area.

3. After this clay shelf is complete, put back the top soil to prevent erosion of the clay and to grow grass and shrubs, etc. Be sure to keep the soil elevation at least 6" below the house framing (i.e. top of the foundation wall) to prevent insect and/or moisture damage.

Before trying any major remedies or expensive waterproofing jobs, you may find that correcting the above conditions can control most water problems.

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