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Proper drainage around the house is the best insurance against damp basements and foundation movement. A drier basement and crawlspace will reduce mold and fungus growth that can be a source of respiratory discomfort for people who suffer from asthma and allergies. Ideally, there should be 1" per foot slope for the first 10' around the house. The soil used to form this slope should be fairly impermeable, such as a top soil with a high clay content. If this grading runs into an uphill portion of the yard, it should be drained into a swale with 1/4" per foot slope carrying the water around and away from the house.

Gutters and down spouts also can be a source of unwanted moisture. Gutters should be cleaned out regularly. Down spouts should discharge at least 5' away from the foundation. Down spout extensions can be made by cutting a 10' length of down spout in half. A U can be trimmed from one end so it can be tipped out of the way when mowing the lawn.

Another source of moisture is sprinkler heads. Sprinklers should be set so they don't irrigate any closer than 5' to the foundation. Plastic films should not be used as a weed barrier under rock or mulch landscaping close to the house. These films will trap moisture. There are breathable plastic fabrics that should be used in these applications.

In areas of expansive soils, consider Xeroscaping using native plants that require a minimal amount of watering. In these areas, it is especially important to keep the soil around the foundation as dry as possible to minimize any potential foundation movement. For additional landscaping information, read Special Publication # 54, Home Landscaping and Maintenance On Swelling Soils. This booklet is available from the Colorado Geological Survey, 303.839-2611.