The check valve: a one-way trip for wastewater
Is your basement ready for heavy rainfall? Without a check valve, water could back up through your plumbing system. Here’s how to protect yourself from sewage backup.
What is a check valve?
Types of check valves
Here are the main models available on the market:
Normally closed valves: Common in homes, they effectively protect against water backup. Some are designed for a single appliance, like a washing machine, while others protect multiple fixtures connected to the same drain system, such as in basement plumbing. Note: It is prohibited to install this type of valve on the main drainage line as it could block the necessary air for venting the system.
Flap valves: Effective against pressure variations, they offer reliable protection even with a low-pressure differential.
Normally open valves: Suitable for certain types of homes, their valve remains open during normal wastewater flow but closes in case of backup.
Electronically controlled inflatable valves: Installed in the main conduit, these devices detect the presence of water. The balloon inflates to block the backup and deflates once the water drains. This model requires no maintenance.
Don’t know what type of valve protects your home? Or not even sure if your home is equipped with one? CAA-Quebec’s Residential Advisory Services can help you find the answers, if you’re a member.
Who pays in the event of a backflow?
Ideally, the municipality or your home insurance company will cover the costs. However, the inconvenience of renovations remains.
Municipal and insurer responsibilities
Some municipalities require the installation of check valves by regulation to avoid being held responsible for damage caused to a building or its contents in case of backup. In such cases, the owner has at least one year to comply. Some insurers require the installation of a backwater valves system following a disaster as a condition for sewer backup coverage.
Additional home plumbing protection
If you own or rent a ground-level home, consider adding the “Water Damage – Groundwater and Sewer” endorsement to your water damage insurance policy. This is also important if your storage locker is in the basement.
Good to know: An insurer may refuse this endorsement if the building is in an area with deficient municipal infrastructure.
Installation and maintenance of check valves
Every check valve must be accessible. An access door or removable panel should be installed if it is inside a wall, ceiling, or under a false floor. Hire a qualified plumber to ensure the valve is properly installed.
Regular valve maintenance should be performed at least once a year, ideally at the beginning of summer. This ensures no debris is lodged in the valve or its hinge.
Tip: If you do it yourself, wear gloves. Remember, it’s wastewater: an essential precaution for your health!
Cleaning steps
If it’s a cast-iron valve with a bolted cover, it’s best to leave the work to a plumbing contractor. Otherwise, follow these steps for a functional valve:
Remove the cover or access plug, either screwed or bolted.
Remove the flap (valve) to clean it and check the condition of the rubber seal. Replace the flap if necessary.
Clean the hinge. It must be free of debris to ensure the valve functions properly.
Reinstall the valve in the correct direction, ensuring no obstruction prevents its movement.
Securely re-screw or re-bolt the access plug and replace the access cover if required.
Small preventive measure to avoid big troubles!
Installing a check valve and performing regular maintenance are essential to limit damage caused by sewage backup. These simple actions can make a significant difference in protecting your home and avoiding costly repairs.