What Causes Water Problems in the Basement?
A wet basement can be a disaster, especially if your basement includes a finished living space. From moldy drywall to ruined furniture, rainfall and melting snow can cause expensive damage. However, very wet basements aren't without hope. Follow these steps to eliminate wetness in your basement.
First, determine which problem is plaguing your basement: condensation or runoff.
Condensation
If you don’t have flows of water after rain or snowfall, but you keep finding damp spots in your basement, the problem is condensation. Condensation collects in your basement as droplets on any surface when humid air is in contact with it.
Condensation problems are usually easier to fix than leaks. One common basement culprit is a clothes dryer. If your dryer is causing the condensation in your basement, make sure the dryer vent doesn't leak and that it's set to vent outdoors.
Also check the drain line that removes water from the indoor part of a central air conditioning system or high-efficiency furnace. If these lines are clogged, they might cause condensation.
You can air out the basement by opening windows and running fans to circulate the air. You can also try turning up the heat in the basement, as warmer air will prevent moisture from condensing on cool surfaces. Another solution is to use a dehumidifier in your basement. These are affordable, easy to use and can help you dry out moist air with minimal effort on your part.
Runoff
If your basement is wettest after a rain or snowfall, chances are you’re dealing with runoff. Runoff happens when water comes through cracks in walls or porous stone.
To rectify runoff issues in your basement, look for places around your foundation where runoff can enter. Your landscape should slope away from the house. If there are places where it slopes toward your home, consider having it graded away. Also look for unsealed cracks on the driveway, which can direct water below the grade of your landscaping.
To fix runoff problems, try patching cracks in the foundation and sealing basement walls using masonry caulk. Patch cracks in the driveway using a patching compound and follow the manufacturer’s instructions. Make sure gutters are clean and properly draining to prevent overflow. Take care of any landscaping grade issues.
Other Problems
If you realize that neither condensation nor runoff is responsible for moisture in your basement, consider calling a professional for help. You could also try installing an interior gutter to collect water and route it to a floor drain or sump pump.
Tips for Keeping a Basement Dry
- Keep your gutters clean otherwise, leaves, twigs and other debris will clog gutters and downspouts, and cause water to pool against the home’s foundation. Install downspout extensions to direct rainwater away from the foundation.
- Some driveways slope toward the house, directing water towards the foundation and causing it to puddle. Be sure that water coming down the driveway is diverted. The grade should slope away from the house on all sides. If that’s not possible, surround the exterior of the basement with gravel and rocks as they easily absorb moisture and dry quickly.
- If you have a partial basement that has an adjoining crawlspace with exposed dirt, cover the ground using 6-mil-thick polyethylene sheeting. Overlap the plastic about 6 inches, allowing the excess to spread up the walls, and use bricks to hold it in place. An earthen crawlspace can cause high humidity in the basement and produce a strong musty smell.
- Your clothes dryer emits lint and moist air. Warm, moist air vented into the house aids in mold and mildew, and may also lead to structural issues. To prevent this, make sure your clothes dryer is vented to the outside.
- Mildew and odors accumulate from moisture caused by cracks or gaps in walls, shifting foundation, faulty floor drains, leaky appliances and more. To control mildew and musty odors, spray the basement occasionally with a mild bleach solution.
- Humidity shows up in the form of condensation on the basement walls and other surfaces. Whether there’s humidity from outside air that's made its way inside, a dryer venting indoors, or any other reason, an exhaust fan, especially in a basement bathroom, will help lower humidity and increase air circulation.
- An exhaust fan isn’t your only defense against humidity. Install a dehumidifier and connect it to the floor drain via a garden hose. Check the drain regularly to make sure it remains unclogged. Use hot water and detergent periodically to keep the drain open and control algae growth.
- Although common in many basements, unsealed concrete flooring is porous and absorbs moisture. When the moisture doesn’t adequately dry, it creates mold. By sealing your concrete floors, you can create a moisture barrier that helps prevent damage to your belongings. For more information, read How to Seal Concrete.
- Flooding is a major concern for homeowners with basements, especially those who live in areas where rainfall or snowfall are excessive. A sump pump is designed to pump out excess water that could potentially cause flooding in the basement. Install a sump pump with a battery-operated backup in case the electricity goes out. You'll need a connection to a drainage system. This project will probably require the help of a professional.