Sewer backup: Why insurance is so important

Dealing with a sewer backup is one of those homeowner nightmares you never expect until it happens to you. Imagine waking up one morning to find your basement damaged by waste water! It’s overwhelming, stressful and definitely gross. Beyond the messy cleanup and expensive repairs, sewage backups can also pose serious health risks. In this article, we’ll walk you through what causes them, the damage they can do, and what you can do to help protect your home (and your peace of mind).

Sewer backups occur when waste water flows back into your home instead of draining out to the municipal sewer system like it’s supposed to. If your drainage system isn’t working, water can come up through the floor drain, toilet, shower or sink and cause water damage to your basement or other rooms. A sewer backup is mainly related to a failure or capacity issues somewhere in the building’s or municipality’s drainage system.

A lot of different things can cause sewage to back up, but some are more common than others. The main ones include:

Blocked sewer lines are one of the main causes of backups. They usually occur when debris (such as fats, oils, coffee grounds and feminine hygiene products) clog the sewer pipes. Tree root infiltration into the pipes is another common cause. If you notice slow drainage, unusual gurgling sounds or a foul odour coming from the sewer lines, there may be a blockage.

Heavy rain or large amounts of melting snow can overload municipal sewer systems, causing waste water to back up into your home.

Neighbourhoods with mature trees and aging infrastructure, as well as low-lying areas, are more likely to have backups. For example, if you live at the bottom of a slope, water can build up more easily and overwhelm the municipal sewer system.

A backwater valve is a device that helps prevent waste water from flowing back into your home. If it’s not installed properly, or it’s damaged or poorly maintained, it won’t provide effective protection. This puts your home at greater risk if the municipal sewer system becomes overloaded.

Sewer pipes, including the underground pipes that carry waste water to the municipal system and the connection between your home and that system, have a limited lifespan. Over time, these pipes can become fragile: they may crack, rust or sag, especially in older neighbourhoods. When this happens, water can’t flow through them as efficiently. This reduced flow increases the risk of a sewer backup because wastewater can no longer drain the way it should.

Sewer backups are often unexpected, but as a property owner, there are things you can do to help reduce the risk. Here are some concrete preventative measures:

A backwater valve, also known as a backflow valve, acts as a barrier that automatically closes if sewage starts backing up into your home. It’s easy and inexpensive to install backwater valves in new builds but can cost a lot to add one to an existing home, since you have to break through the basement slab to do so. It’s recommended that you have a professional perform the installation.

Is a backwater valve essential? Yes. Combined with other measures, it can help you avoid costly repairs. Even if the backup comes from your municipal system, you could be responsible if you don't have a properly installed and maintained backwater valve. Many municipalities include this in their bylaws.

There are three types of backwater valves:

Normally closed horizontal backwater valve: As the name suggests, this type of valve is usually closed. When waste water flows through the system, the valve opens to let the water pass. But if the sewer backs up, it will come up against the closed valve, which will stop it from flowing back into your home.

This type of valve prevents air from circulating, so it can’t be installed on the main drainage line (also known as the main collector) because this line has to allow for sewer ventilation.

Normally open horizontal backwater valve: As the name suggests, this type of valve is usually open. This allows air in the system and wastewater from the protected building to flow freely. During a sewer backup, the valve lifts to prevent wastewater from entering the building.

A normally open backwater valve can only be installed on the main drainage line for a single-family home. Some municipalities don’t allow backwater valves to be installed on the main drainage line (or main collector).

Insert vertical backwater valve: Commonly called a “squeeze-in”, this type of valve is designed to be installed in a floor drain, also known as a floor cleanout. It’s inserted into the pipe after removing the grate and stays in place thanks to a compression ring.

While they’re not prohibited by the National Plumbing Code, some municipalities don’t allow them to be installed.

A French drain, also called a foundation drain, is a perforated pipe installed at the base of the foundation to capture water that accumulates in the soil and direct it away from your home. The water then flows toward a ditch, the municipal sewer or a catch basin connected to a sump pump.

By removing water from around the home, the drain helps prevent infiltration, excessive humidity and hydrostatic pressure (pressure on the foundation) that could cause cracks and structural damage.

When the drain is damaged or clogged, it’s less effective, which can increase the risk of backup. In many cases, a professional can do a camera inspection to check on its condition and spot issues before any damage occurs. Otherwise, it may fill up with unwanted materials, leading to costly repairs.

Sometimes there just isn’t enough slope for a French drain to be effective. That’s when a sump pump can come in handy. In this type of system, water collects in a catch basin in the basement, where the sump pump takes over to push it outside. For added peace of mind, you can add a backup like a battery or a second pump to keep the pump working if the power goes out. It’s also important to make sure your sump pump can handle the volume of water coming in. And don’t forget about annual maintenance (pump operation, basin cleaning, battery testing) to minimize the risk of damage.

Basement garages are particularly vulnerable to water infiltration. The catch basin located in front of the door is used to collect water that runs down the slope of the property and discharge it into the municipal system. To keep it working properly, regular maintenance is key: remove leaves, sand, debris or tree roots that block the grate, and check that the drainpipe is clear. It’s also important not to direct your downspouts toward the slope leading to the garage, as this puts extra pressure on the basin and increases the risk of water infiltration.

Good stormwater management around your property helps prevent water from building up near the foundation and reduce the risk of damage or sewer backup. To do this, you can:

• Keep a positive slope of about 2%¹ around the house so rainwater naturally flows away from it
• Maintain surface drainage features such as eavestroughs, downspouts and drainage grates to prevent water from accumulating near the foundation
• Reduce the load on the French drain by ensuring good surface runoff, especially during heavy rainfall or rapid snowmelt

Adopting a few simple habits can help keep your water drainage system in good condition and reduce the risk of backups. Here are the main measures to follow:

• Regularly clean drains and pipes to prevent debris buildup and blockages
• Check that the backwater valve and the sump pump are working properly, including the float switch and backup power source. Annual maintenance—ideally in the spring—helps remove dirt and deposits that could prevent them from functioning properly
• Ensure that downspouts discharge water away from the foundation, using well‑installed extensions directed toward a safe area
• Have your water drainage system periodically inspected by a professional to detect any signs of wear, blockage or the presence of iron ochre in the drains

Sewer backups can happen to anyone. Homeowners, co-owners, tenants—no one is completely protected. Even if your unit is located on an upper floor, you might have belongings (like a photo album or your child’s artwork) stored in the basement or in common areas, which exposes them to risk.

Basic home insurance generally doesn’t cover this type of incident. It typically only includes common water damage, such as from an overflowing bathtub or a burst pipe.

To get coverage for sewer backups, you’ll need to add additional coverage (a specific endorsement) to your home insurance policy. Why? Because the damage can be costly. According to the Government of Canada, it costs more than $40,000 on average to repair basement water damage. When choosing your insurance amount, take into account the costs related to demolition and restoration, drying and decontamination, temporary relocation and replacing furniture and equipment like your furnace.

Are you already insured by Desjardins Insurance? Go to your online account to check your current coverage.

Every situation is unique. To figure out how much coverage you need, you can make an inventory of everything you keep in the basement and estimate how much it’s worth. Include things like furniture, electronic devices, game consoles, sports equipment and your furnace. And don’t forget about other possible costs like demolition, rebuilding or a temporarily relocation.

You should also ask yourself if you live in a high-risk area (this would include older neighbourhoods, property near a waterway or below street level, for example). Finally, it’s important to review your home insurance coverage regularly, especially if you’ve renovated your basement or added any costly equipment.

If you experience a sewer backup, remember: safety is your #1 priority. Before you do anything, make sure that it’s safe to shut off the electricity in the affected area. If it isn’t, leave the area and seek assistance. Once the electricity is off, make sure you wear gloves, boots and a mask to prevent contact with contaminated water.

Once you’ve taken these precautions, contact your insurance company to report the loss. Your claims adjuster will be able to guide you through the next steps, such as calling a certified plumber or restoration company to start cleanup and prevent additional damages.

If the problem stems from the municipal system, contact your municipality or the public works department. Keep your receipts, take photos and make a list of your damaged belongings. This information will be helpful when you make your claim.

Protection that makes a difference

By taking preventative measures, like maintaining your equipment and managing water around your home, you can help reduce the risk of a sewer backup. And the right insurance coverage could help limit your out-of-pocket expenses to complete the necessary repairs. At the end of the day, a bit of foresight and the right protection can go a long way toward keeping your peace of mind. Your home and your wallet will thank you.

Learn more

1. Focus on Backwater valves, Institute for Catastrophic Loss Reduction, https://www.iclr.org/wp-content/uploads/PDFS/focus-on-backwater-valves.pdf

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