How Do I Detect Indoor Humidity Problems?

Watch for condensation on windows, a musty smell in the basement, and visible mould or discoloration on walls and ceilings, since these are the earliest signs your home is holding more moisture than it should. CMHC recommends keeping indoor relative humidity between 30 and 50 percent depending on outdoor temperature to avoid condensation damage.

Excess indoor humidity in a Saskatoon home usually comes from one of a few sources: inadequate bathroom or kitchen ventilation, a basement that is not properly managing groundwater or surface water, or a furnace and ventilation system that is not moving enough fresh air through the house. CMHC publishes detailed guidance for Canadian homeowners on managing moisture, because our climate swings from very dry winter air, which pulls moisture out of wood framing and finishes, to summer humidity that can overwhelm a poorly ventilated basement. Both extremes cause real problems if the home is not managing air exchange properly, and the fixes for one can make the other worse if applied without thinking through the season.

The most reliable way to check is with an inexpensive hygrometer placed in the basement and in a bathroom, since those two spots are where problems show up first. Persistent readings above 50 percent, especially in winter, point toward a ventilation or moisture source problem rather than normal seasonal humidity. Visible signs to watch for include condensation pooling on the inside of windows every morning, a musty smell that does not go away with cleaning, peeling paint or bubbling drywall near the base of basement walls, and visible mould in corners or behind furniture pushed against an exterior wall where air does not circulate.

A bathroom fan that vents to the attic instead of outside, a dryer vent that is disconnected inside a wall cavity, or a sump pump pit without a sealed lid are common, fixable culprits in older Saskatoon homes. Fixing the source, rather than just running a dehumidifier indefinitely, protects the home's structure and air quality over the long run and avoids the kind of hidden moisture damage that shows up during a home inspection at resale, often at the worst possible moment in a transaction.

Grading around the foundation matters too. If the ground slopes toward the house rather than away from it, surface water collects against the foundation every time it rains or the snow melts, feeding a basement moisture problem that no amount of indoor ventilation can fully solve on its own.

If you are preparing to sell, an unresolved humidity issue is exactly the kind of thing that surfaces in a buyer's inspection and affects negotiations, so it is worth addressing before you list rather than after an offer is already on the table. Get your hand-reviewed valuation from Joel Dyck.