Basements are inherently prone to flooding due to the fact that they are built partly or entirely below ground level. And thanks to gravity, water easily finds its way from high to low ground. If the water level around your home rises above the basement floor, then gravity will naturally move that water into your basement.
There are a number of reasons why basements flood.
- Surface inflow
Basement flooding is common during wet weather. During heavy rains or rapid snowmelts, surface water may accumulate around the house and find its way into hard surface depressions such as driveways or basements.
- Structural issue
If you notice a tiny wet spot in your basement, don’t assume it’s nothing. It could be a sign of a structural issue, like a crack in the foundation floor, that will allow groundwater to seep in. If left unresolved, that tiny spot could turn into full-on flooding that may cost you thousands in carpet damage, basement repairs and restoration.
- Foundation drainage failure
The foundation drainage system of your basement works to keep the ground water level lower than the basement floor, either by gravity or by pump.
Gravity foundation systems (weeping tiles) may get plugged by fine sediments or degrade over time. As a result, the system will cease to drain water by gravity. On the other hand, a sump pump built into the basement, which pumps out water around the foundation and discharge it into the lawn, could fail if they are plugged or can’t keep up with the incoming water.
- Sewer backup
By design, sanitary sewers have a path to the home called the sanitary sewer lateral. This allows domestic wastewater to flow from your home out to the sewer pipes. But when the sanitary lateral fails, sewage could backflow into your home.
The sanitary lateral fails if it is blocked by what is being flushed down the toilet, it is damaged due to aging or if the sewers are full. You’ll need a licensed plumber to carry out an assessment and resolve the issue properly.
- Broken or malfunctioning pipes
Plumbing failure can sometimes be to blame for basement flooding. A flood could break into the home’s internal water supply line in many ways – burst pipes, damage to aging plumbing equipment or failure of the hot-water tank.
What to Do When Your Basement is Flooded
- First thing to do is switch off any power around the area. Never step into a flooded area before doing this. Call a qualified electrician if you’re not sure how to turn the power off.
- If it’s not due to rainfall, it’s best to call in a licensed plumber to help you check the drains, sewers and pipes for the cause of the flooding.
- Once the issue has been resolved, act fast in removing water from the basement. The longer the water sits, the more damage it will cause. Make sure to wear protective gloves and boots (and a nose plug if the smell is rank).
- Remove all the stuff in your basement and allow everything to dry for 48 hours. If they remain wet after that, it’s best to discard those items to avoid mould or mildew. Don’t be tempted to keep soggy carpets or rugs, as they may carry bacterial contaminants.
- Scrub and disinfect every inch of your basement, from floors to walls, cabinetry and hardware. Then allow to air out until totally dry.
- If you have flood insurance, you may need to take photos of the damage for documentation purposes. Confirm your coverage and claims process.