Guide to Basement Moisture Control

A damp basement is nothing homeowners want to deal with. Often this is the reason why a great deal of basements (translate to extra living space) are wasted and given up as hopeless causes. Everyone knows the damp basement. It has that classic dank, musty smell you remember from your grandma’s basement. Besides just being annoying, dampness can bring water damage to things stored there and influence mold growth and the rotting of anything wood. The other downside is that it can be the cause of allergies, itchy skin and nasal passages. Fortunately, the problem of a wet basement isn’t a hopeless one. There are ways to deal with basement moisture, even to the point where you’re comfortable with eventually turning it into a family room.

The first thing to do is diagnose the problem. Where is the moisture coming from?

One such cause is inadequate ventilation. This can be solved with a portable refrigerated dehumidifier. Other ways to solve the problem are to dry clothes outdoors and vent the clothes dryer outside the house. Instead of having carpeted flooring, try to use an alternative as carpet retains moisture.

People would be surprised at how much a good quality bathroom fan will help regulate moisture. Another option, especially for the muggy summer months, is an air conditioner that removes water from incoming air rather than just cooling it. Look for an air conditioner with a high “latent heat” rating instead of a good “sensible heat” rating.

Another source of moisture could be sewer and water line leaks, a leaky roof, bad caulking around windows and doors, or poor surface drainage in the areas around the house. This poor surface draining could be caused by anything from the slope of your land, low spots or a lack of roof drainage systems. Going around the house to check for any one of these problems could easily lead to the solution. Most often, damp basements are caused by problems on the outside of the house, which can usually be easily fixed. Something to think about as you’re checking around the house is to ask, “Where does the water go when it rains?”

Ensure that the downspouts and gutters are cleared and directed away from the house and the drainage doesn’t flow next to the house’s foundation. Splash-blocks can help with this problem, however depending on the slope the house sits on, this may not be possible. Sometimes sloping the ground around the foundation of the house will help this problem.

President of StreetSmart Real Estate, Inc., Kevin Myers recommends these solutions:

“Construction plastic can be added to give ever better protection. Subsurface drains or French drains can be used successfully in many instances if they are installed and maintained properly. On larger lots, a swale (artificial depression) can be built to direct surface water off-site.”

Taking these precautions will definitely help moisture problems in the future and will make your basement a happy place, rather than a place to fear.

Kevin Myers, What to Do About a Wet Basement

Choosing a Dehumidifier, CMHC