Trained Eye


Water in Garage


IWe live in a 25 year old home in the Southeast part of the City. Every time it rains hard, one side of our basement floods. We have window wells. It doesn't appear that the window well drain is plugged. The basement is finished with carpeting, panelling, and a stippled ceiling. To "clean up" we rent a Rug Doctor to suck up the moisture and then turn on fans for days, until the rug is dry.

My question is twofold. First, is there any effective way of preventing this flooding? I say move, but my husband likes it here. I think if it rains hard one more time this year I may be able to convince him, as he does the clean up! Secondly, I am afraid this moisture may cause health problems for us, not to mention our house. There must be mould spores everywhere. My husband doesn't seem to be concerned. Please advise.


The problem described by Mrs. is not an uncommon problem for basement foundations. According to a recent survey by Health and Welfare Canada, approximately 38 percent of Canadian homes had indications of excessive dampness or mould. I’m afraid I can’t give the reader any suggestions to improve her husband’s indifference, but at least he’s willing to do the dirty work. I will, however provide a few possible causes and solutions to this problem.

Moisture is the biggest enemy of houses and providing a means of keeping it away from our foundation walls is essential to longevity of the building as well as keeping the basement dry. When a house is built, the exterior of the basement walls are waterproofed and a drainage system, often referred to as weeping tile, is installed to divert excess ground water into a sewer or sump pit. This helps prevent the moisture from entering our foundation walls through small openings or cracks. Moisture may also enter a foundation due to “hydrostatic pressure” from saturated soil.

The systems installed generally work very well for a number of years after the home is built, but may deteriorate and not provide adequate protection from seepage. Most older homes have clay weeping tiles that become plugged after many years of use. The effectiveness of these tiles and the bitumen based waterproofing on the foundation can become negligible. This is when many basements start to leak, and attention to the grading and drainage systems becomes critical.

The first step in finding a solution is the same thing most home inspectors do upon arriving at a property they are inspecting. Take a walk around the house and look at the surrounding grading, vegetation, driveway, sidewalks, roofing, and drainage systems. The majority of cases of moisture intrusion into a basement can be directly attributed to a defect or failure in one or more of these areas.

The roofing must be in good shape and should be properly draining into clean eavestroughs and downspouts that are secure and free from leaks. The downspouts should have 3’-5’ extensions attached to divert water away from the foundation. The soil beneath these extensions and adjacent to the house should have a proper slope (1” per foot for 6’) or it may have to be built up and sodded. Settlement and erosion of the soil in this area is probably the most common condition identified in a home inspection.

Next the vegetation around the house should be checked. It should never come in contact with the house or the roof. Siding, roofing, windows and all wooden trim on a house must be allowed to dry out after getting wet. If you can’t walk between the plants and the house, trimming is needed. If trees are very large and/or too close to the house, they may cause damage to foundations or subsoil systems.

If all of these systems are in put in good order and moisture is still getting in, then it may be time to call in a reputable foundation contractor to evaluate the situation and provide estimates for repairs. These can be costly and vary widely in approaches, so multiple opinions are suggested.

The concern over mould growth is well founded. This is difficult to address unless the homeowner is willing to strip the wall coverings and check behind. One suggestion may be to add a disinfectant to the Rug Doctor soap when cleaning the carpets.

For more information, C. M. H. C. has put out an excellent manual entitled Investigating Diagnosing & Treating Your Damp Basement which may be purchased directly from their offices or website.