Wet basement? Here are some things to check

Hey there, time traveller!
This article was published 06/05/2014 (4338 days ago), so information in it may no longer be current.

The snow has finally melted — thank goodness!

Talking with my neighbour the other day, she mentioned that their home had water in the basement. A wet basement is more than a nuisance. If your basement includes finished living space, any kind of moisture can ruin carpeting, drywall and wood framing. Even if you have a crawl space or just use your basement for storage, a simple case of moisture can spawn harmful mold.

In my neighbour’s case, the water is coming from the melting snow. Runoff that is not routed away from the house can percolate through the porous topsoil and then stop at the compact soil near the base of the foundation. Hydrostatic pressure forces the water through gaps or cracks in walls and footings. The water can also move through porous walls by capillary action.

Look for ways runoff can enter your basement or crawlspace.  There are a number of things to check:

• The ground outside should slope away from your house at least one inch vertically for every one foot of horizontal travel
• Make sure downspout runoff is not pooling near the foundation
• Check that the downspout seams are not leaking
• Make sure gutters are cleaned so that they will not overflow; add downspout extensions if needed so that gutters drain 4 feet away from the house onto splash pads
• Check that driveway curbs are channelling runoff to the street.  
• Unsealed cracks on the driveway surface; these can allow water to collect below grade.

The simple fix is to start by patching any cracks in your foundation or basement walls with a polyurethane masonry caulk. For larger cracks, use hydraulic cement which expands as it dries. For both basements and crawl spaces, address outside entry points next by patching cracks in the driveway using cold-mix asphalt patching compound.  For a concrete sidewalk or driveway, use ordinary cement.

If the wet basement symptoms act like runoff but occur all the time, high groundwater is probably the source of the problem.  Unless the foundation is surrounded by soil that has a high clay content, which can hold rainwater and snow melt for months, runoff problems usually come and go as storm water drains away.

If, on the other hand, the basement is consistently wet long after a storm, or if water is flowing through your walls or bubbling up where the walls meet the floor, there is probably a subsurface water problem.

Solutions range from the relatively simple (injecting absorbent clay into the soil and urethane caulk into cracks) to the more involved (creating and installing a sump pump). A contractor may also suggest combining an interior system (sump pump) with perimeter drainpipe or, an exterior system which covers the foundation with a waterproof membrane and lays perimeter footing drains in a bed of gravel.

Considering the potential high cost of subsurface water problems, doing it right is crucial. A pro should be used.

Charlene Kroll is a community correspondent for North Kildonan. She can be contacted at krollcharlene@gmail.com