Your basement is an often overlooked, but surprisingly essential part of your home; it provides added living space, storage, and keeps less-attractive home appliances out of sight (we’re looking at you, furnace and hot water heaters.)
But all that extra value added to your home does come at a price; most Alberta basements are almost entirely below ground, and that means they’re closer to the groundwater table, the boundary between generally dry soil and water-saturated soil.
Local conditions and drainage can affect how deep the water table sits below the surface, but if the ground is saturated after rainstorms or in the springtime as snow melts, moisture can make its way from the soil to your home’s foundation, then into your home through cracks or even holes, and can cause some real headaches.
Think of the ground outside your home, your exterior foundation wall, and your home’s interior walls as three separate zones that protect your basement from moisture. Each of these zones can contribute to water entering your home, so steps must be taken to keep each one working as intended. Learning how to waterproof each zone will help protect your basement, and keep moisture outside where it belongs.
Zone 1 – Exterior ground
Your first step begins high above the ground, when you ensure your eavestroughs and downspouts are clear of leaves and other debris. Blockages can cause water to overflow gutters and pool near your foundation. Make sure no blockages exist, and that your leader system directs water away from the home.
You can grade soil away from your home to encourage proper drainage; a 3 meter slope with about a 15 centimeter drop is a safe start, and should keep surface water moving away in the right direction. If you notice water collecting on the ground, consider installing a gravel trough, or French drain, in the area to direct surface water away (but ensure your local building codes allow it first.)
Zone 2 – Exterior walls
Ideally, if you have taken a number of preventative steps outside, your home is already fairly safe from moisture leaks, but there are ways to improve your odds when it comes to your home’s foundation.
Check your foundation for cracks; even tiny spaces on the exterior or interior cement can allow water to enter your home. You can patch these cracks with hydraulic cement which, when mixed properly, can create a watertight seal in around 5 minutes, even if water is moving through the crack while you’re doing it.
There are a number of waterproof sealants on the market that can be brushed or sprayed onto foundation walls to create a rubber-like, impermeable water barrier. This is a fairly involved process however, so take time to plan and prepare for it, or call a professional to ensure expert workmanship.
While window wells are meant to keep soil away from your basement windows, make sure they aren’t filled with standing water that can seep in through the window frame. Galvanized steel or plastic window well liners that extend below-grade in flood-prone areas can act as dams to hold back water, and window well covers that securely fasten to your home can act as ‘umbrellas’ to direct water away to drainage.
Zone 3 – Inside your home
Finally, you can waterproof the walls inside your basement.
Waterproof coatings similar to exterior mixtures already mentioned can be applied inside over the cement or concrete blocks making up your foundation wall, acting as a final line of defense against encroaching moisture. They may be specifically manufactured in white or neutral colours for inside use, but can easily be painted once applied. These coatings usually dry in roughly 3 hours, meaning you can apply multiple coats if necessary. (Important: do not alter the poly barrier in an undeveloped basement.)
A sump pump draws excess groundwater away from your foundation and directs it to appropriate drain pipes, an absolutely essential fixture if the water table around your home is especially damp, so confirm regularly that yours is operating correctly.
Check the float by slowly pouring water into the pit until the pump turns on; it should also turn off once the water has been drained away. You should also check that no debris is in the pit, as this can cause the float to malfunction.
If the pump doesn’t switch on, check the electrical connections to ensure they’re plugged in properly, and that the breaker hasn’t tripped. If the electrical supply checks out, your pump may be malfunctioning, and you should consider repairs or replacing it. Most sump pumps have a recommended lifespan of roughly 10 years.
The humidity in your basement can also create issues; lower-floor humidity in Alberta during warmer months should generally be between 30% and 50%. You can easily check it with a hygrometer or humidity sensor, and consider a dehumidifier if your levels constantly exceed acceptable levels.
Finally, keep an eye out for any plumbing leaks affecting appliances or pipes on upper floors of your home. Water from leaky pipes often flows through the floor or walls, well out of sight until it arrives in your basement, appearing as seepage.
If you stay ahead of water and moisture issues, your basement will stay warm and dry for the life of your home!