If you own a home with a basement, chances are you’ve noticed dampness at some time. It may be as unremarkable as condensation after a hot shower or as shocking as an ankle-deep “lake” following heavy rain.
Whatever the circumstance, you’ll want to investigate and control excess moisture. That’s because persistent dampness can lead to mold growth, rot, insect infestation, and even accelerate settling and cracking of your foundation. All are considered maintenance-related problems typically not covered by homeowners insurance.
Basement moisture comes from condensation, leakage, or both. Generally, condensation is easiest to fix. Solutions may include eliminating sources of moisture (improperly vented clothes dryers, indoor clothes lines, plumbing leaks); adding exhaust fans and dehumidifiers; and improving air flow (getting rid of clutter and moving boxes off the floor can help). If you notice moisture during warm weather, condensation may be to blame.
Leaks can be trickier to treat, but simple fixes often yield big gains. You may need a combination of steps to control surface water and seal basement walls.
CONTROL SURFACE WATER
- Make sure downspouts channel water away from your foundation. Install extenders if your downspouts discharge next to the house. Keep gutters clean and in good repair.
- Consider adding covers to window wells and outside stairwells to deflect rainwater.
- Regrade your landscape so water flows away from your house. Standing water in the yard acts like a “reservoir” for your basement. Driveways and paths should slope away, too.
- If regrading is impractical, install French drains to direct water away from your house. Typically, a French drain consists of a narrow gravel-filled trench lined with landscape fabric. It drops at a 1% grade (one foot per hundred feet), combining gravity and the porosity of the rock to draw off excess water. The Web has many sites explaining how to build French drains.
SEAL BASEMENT WALLS
- Patch visible cracks in basement walls. Consider brushing interior basement walls with a waterproof coating. See the June 2002 issue of Consumer Reports for ratings on coatings. (Note: Depending on the severity of the problem, some contractors say such quick fixes can make things worse, trapping water inside the wall.)
- A better – and more costly – solution may be waterproofing the outside of your foundation with a barrier of plastic, rubber, or brushed-on sealant. That means major excavation alongside your home, likely with the help of an experienced contractor.
If your problem requires more than do-it-yourself fixes (like excavation or, perhaps, you’re thinking of installing a dry well and sump pump), take care when hiring a contractor. Get bids from several professionals, ask friends and relatives for referrals, and check the contractors’ registration status by calling the Department of Labor and Industries at 1-800-647-0982 or accessing its Web site at www.lni.wa.gov.