New Techniques for a Dry Basement

Exterior Seal

• Keeping moisture out of the basement in the first place is far better than trying to deal with the dampness once it is in the basement. The best way to keep a basement dry is to apply some of the new products that have been developed to waterproof the exterior basement wall. Tar and tar-based products can be painted onto the exterior of the foundation wall, or the wall can be wrapped in a variety of plastic sheet products designed to keep water away. It's obviously easier to apply these techniques during new construction, but with excavation they can be added to existing houses. Landscaping should be contoured to direct water away from the foundation walls, and eaves should either have gutters leading to drainpipes, or have a very large overhang so that runoff doesn't land on the ground near the foundation walls.

Interior Waterproofing

• The interior walls of a basement can be painted with waterproof paint to keep dampness and moisture out. This is not as good a solution as applying an exterior seal, because if you are stopping the moisture at the interior surface of the wall, it means the moisture is in the wall. However, this solution doesn't require digging a six-foot trench all the way around your house. Opinions vary on the effectiveness of interior sealing. In a situation where it's your only option, it's better than nothing.

Dehumidifier

• For basements that don't actually have water running through them, but are plagued by a musty smell caused by dampness in the air, a dehumidifier can work well. The problem is greatest in the summer. The damp, hot air of the outdoors will cool meets the colder underground air in the basement and is cooled by it. The cooling air releases its moisture, which condenses on the walls, ceiling and floor of the basement. A dehumidifier will remove the moisture from the air and put it all into the dehumidifier reservoir instead of allowing it to dampen all the basement surfaces. The reservoir water can be carried back outside and put on the garden, where it belongs.