Renovation & Design

ASK THE INSPECTOR: Moisture mystery easily solved, not easily fixed

Many homes have a catch basin like the one pictured above that is connected to the municipal sewer system.

QUESTION: My house was built in 1950 and originally had downspouts from the eavestroughs emptying into the basement. I'm not sure when the original owners switched them to the outside, but that's where they are today.

I don't believe we have weeping tiles. Is that even possible, given the building requirements for that time? Why I say this is my husband dug down beside the back wall of our basement once trying to fix a persistent run-off water leak and no tiles were visible. Would they have been?

Our basement is wet every spring and often after a heavy rain. So if we don't have weeping tiles, can a sump pump be installed in the basement? Where would it pump water to? I would like to solve our wet-basement problem but don't know where to start.

Sincerely, Jo-Anne Irving

ANSWER: Even if you do have weeping tiles installed in a home of that age, there's a good chance that they're plugged or damaged and not working properly. There may be some things you can do to minimize the wet basement without expensive excavation, but the success may be limited.

Could your home have been built without weeping tiles in 1950? Sure. Depending on where you live, the soil conditions, the builder and the local building officials, any or all of these variables would factor into the presence or absence of these important components of a home's moisture-management system.

In areas with very sandy soil, where drainage is good, weeping tiles may not have been used at that time. But in many areas, with our notorious Red River gumbo clay soil, weeping-tile installation was standard practice even before your home was built.

It should be easy to determine if such a system is in place by looking for its exit point. All weeping-tile systems have to terminate somewhere, to drain the excess ground water that they collect. This could be a sump, which may be a modern plastic pit or an older concrete-lined depression beneath your basement floor slab.

More likely, your home will have a catch basin connected to the municipal sewer system. This catch basin is usually installed in conjunction with your basement floor drain, so locating this drain should be the first step in your investigation.

The drain cover may be hidden underneath flooring or other material in your basement. If you have a finished basement, especially with an older wooden subfloor or carpet, this is a strong possibility. The floor drain in a home your age should be located somewhat centrally, often at a point where the floor slab slopes to its lowest point. If you have older carpeting, try to find the lowest point and tap on the floor lightly with a hammer until you hear a metallic or hollow sound -- that's likely the cover of the floor drain.

Once this is located, cut away the flooring, remove the cover and look inside the round opening with a flashlight. You should see several cylindrical openings in the sides of the concrete, often running in different directions. If there are only one or two of these openings, these may have been drains from the original interior downspouts you mentioned. That would suggest that weeping tiles were not installed. If there are four or more of these holes, typically running from each side of the foundation, then weeping tiles were probably installed.

Removing the drain cover for inspection during heavy rains, or when the snow is melting in the spring, will often tell you if they are functioning at all. If there's no water dripping or running from the ends of the round openings into the water at the bottom of the catch basin, then they are plugged or just old downspout drains that are not in service anymore. Either way, they will not help to prevent dampness in your basement.

If there are several drain openings visible but you're not sure if they're functioning, you could call a rooter technician or plumber to do a cleaning and scope of these openings. Most rooter companies have snake video cameras that can be inserted into the old weeping tiles through the catch basin, which can visualize and record what is going on inside these crude pipes. If there is significant blockage or damage, the metered snake will see it and not be able to travel to the end of the subsoil portions of these drains. That will confirm if they could be functional or not.

If there is a sump where the weeping tiles terminate, a similar approach could also be taken. That could be the final determination if excavation repairs may be necessary.

If you can't locate a catch basin, or have a floor drain without openings in the concrete at the sides, it's likely that weeping tiles were never installed. In that case, installation of a sump pit, with some holes or openings to collect excess sub-slab moisture, may have limited success in drying the basement. This would also require installation of a sump pump and proper piping that discharges to the exterior of the home. Unfortunately, this type of arrangement will only collect water from the soil underneath the home, not surrounding the foundation where most infiltration occurs.

Improving the grading outside your home to provide a slope away from the foundation is the first step in preventing a wet basement. That should be followed up by extending the downspouts up to three metres, to further channel rainwater away from the wet foundation walls. If both of those improvements don't significantly reduce the amount of moisture entering your basement through the foundation, professional excavation and weeping-tile installation may be your only hope.

Ari Marantz is the owner of Trained Eye Home Inspection Ltd. and the President of the Canadian Association of Home & Property Inspectors-Manitoba ( Questions can be e-mailed to the address below. Ari can be reached at (204) 291-5358 or check out his website at



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