How to Prevent Mold in your Basement

According to Mike Holmes, recognized as Canada’s most trusted contractor, the key to preventing basement mold is to ensure that your basement is properly insulated because it provides a thermal barrier. If the basement is not properly insulated, mold is inevitable. Holmes explains why:

When air, which is full of moisture, leaks into that insulation, it will inevitably lead to mould. Here’s why: Your basement, like every room in your home, has its own natural air convection. The air nearest the ceiling is warmer, and the air nearer the floor is cooler. The cold air at the bottom pushes the warm air up. As it rises, it comes into contact with the cooler exterior wall and releases the moisture it’s holding. It condensates. That air and moisture — if it’s able to get into the batt insulation through a gap in the seal — will wick into the insulation. (Mike Holmes)

According to Holmes, a thermal barrier is not enough to preventing condensation. Instead, he recommends a thermal break to stop the hot air from meeting the cold. With this in mind, he recommends that spray foam insulation or rigid foam insulation be used because it provides the thermal break required to trap any moisture.

These are great tips for preventing mold in your basement, particularly if your basement is unfinished and you are thinking about finishing it to get more use out of this space. However, what can you do if you do have mold in your basement?

If you’ve started to notice a musty smell in your basement, you may already have mold in your home.

Basements have the potential to be dark and damp places. Add water and moisture to this equation and you have the perfect conditions for mold growth.

The odour you smell is most likely caused by the mold excreting mycotoxins. Molds will release spores in the air as a defense mechanism to find more moisture and food, contributing to further mold growth

If you do have mold growth, the key is to contact a professional to investigate the situation.

To prevent future mold growth in your basement, here are some tips that you may want to consider:

1. Ventilate. Excessive moisture causes moldy musty basements. Open windows at opposite ends to provide adequate cross-ventilation.

2. Check the drainage around your house. Porous basement walls could transmit moisture from the ground outside during rainy spells, and the trapped moisture increases the humidity in your basement. Make sure the ground slopes away from foundation walls, and that downspouts extend 6 feet or more from the house.

3. Waterproof the basement. Look for cracks in the walls and floor and seal them with hydraulic cement. Apply concrete waterproofing sealer where the floor meets the wall.

4. Buy and install a dehumidifier to remove excess moisture.

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