Basement flooding can happen anywhere, even in homes that have never experienced it before. Heavy rain and snow melt are the most common causes. Because water can enter your homes in different ways, preventing it requires different solutions.
Install a check valve
All the drains in your home merge in your basement and connect to the municipal (Sanitary and Storm Water) system under the street. During a very heavy rainfall, the municipal storm water network can reach capacity and the storm water (or storm water combined with sewage water) can lead back towards your house and come out of your drains, which can cause flooding. It is very important to consult your plumber as to whether you live in an area with a combined system or separate system as this can impact the number (and location) of check valves required.
To prevent this risk, you must install a check valve (also known as a backwater valve), which blocks the wastewater and storm water from returning. Please also consult your plumber as to what type of maintenance is indeed required and how often they must be verified to ensure that they are working well.
Fix foundation and floor cracks
When water saturates the ground near your foundation wall, it can enter in any weak points like cracks in the wall or floor.
To prevent this risk, you need to seal these cracks from the inside (by removing drywall) or outside (by excavating). The best time to look for cracks on the inside foundation wall is if the foundation wall isn’t covered by insulation and drywall. In such a case, you can test for cracks by watering for about 20 minutes the ground outside the foundation wall, one section at a time, and then look for water infiltration in your basement. This can help you find the exact location of the cracks.
Install and repair window well covers
A window well is a recessed area around a basement window that extends below the ground level. If you don’t have a window well or if there are gaps in it, water could accumulate around basement windows and enter your basement.
To prevent this risk, ensure that you install window wells and covers, and that water from the surrounding area does not get through. A bed of stones will drain any water at the foot of the window.
Repair or install French drains and sump pump
A French drain (also known as weeping tiles or foundation drains) is a type of underground drainage system that helps to redirect surface water and groundwater away from an area. It is typically installed under your lawn, near the base of the foundation. Over time, a French drain system may become blocked by accumulation of silt or tree roots, which means it is no longer functional. A sump pump also needs to be checked and/or replaced when it stops working.
To prevent this risk, you need to have a functioning French drain system, which will help collect water underground and move away from your foundation. It must flow into a sump pit in your basement, where a sump pump will move the water back outside to the municipal wastewater system, to your lawn, or to both.
Clean your gutters and extend your downspouts
Gutters collect rainwater from your roof and channel it away from your house’s foundation. However, leaves and other debris can get into gutters and prevent its usefulness. Water collected in your gutters flows down in downspouts, but without proper downspout extenders, water will pool near your foundation.
To prevent this risk, you must clean your gutters at least once a year and ensure that the downspout extends 1.5 meters or more from your house’s foundation. For more information, see Directing gutters to the right place.
Slope your land away from your house
Over time, your lawn may erode near your house, which means rainwater will slope towards your foundation wall.
To prevent this risk, ensure that you slope the ground away from your home.
Add soil near your foundation wall so that the ground is higher than the rest of your property. A landscaper may recommend other solutions and materials, such as river stones, flower gardens, and so on.
Ensure your basement floor drain is accessible
Your basement is required to have a drain. It is typically located near your hot water tank. If your drain is clogged or if it has been covered by carpet or flooring, it won’t provide a way for water to leave your basement in the event of a flood.
To prevent this risk, ensure that your floor drain is functional and accessible.
Clean your driveway drain
If you have a sloping driveway, water will naturally flow down your driveway. If you don’t have a functioning drain, then during a heavy rainfall water may accumulate and eventually enter your basement, which will cause flooding.
To prevent this risk, you need a proper drain that is cleaned regularly. Consult with a professional drainage contractor. They can assess your specific situation and provide tailored advice on the best type of driveway drain for your needs.
Leaks and breaks of the water supply-line
Apart from floods brought on by heavy rainfall, floods can also be caused by due to a broken water supply-line pipes in your bathroom, kitchen, or hot water tank.
To mitigate the effects of this risk, you should add water detectors in your home. Some can alert you on your smartphone. Also, make sure everyone in your house knows the location of the water shut off valve so they can stop the leak as soon as possible.
Other measures
In addition to the preventative measures above, it is a good idea to be ready for a flood.
- Buy a water transfer pump and hose, which can be placed in a pool of water and can pump it away.
- Add back-up power to your sump-pump to ensure it will work in the event of a power outage.
- Have sandbags ready to deploy at the top of a down-sloping driveway to minimize the amount of water flowing down, or around window wells, or other places that water may enter.