What Winnipeg Homeowners Should Know About Backwater Valves.

Normally Closed Backwater Valves

Normally closed backwater valves protect your basement from being flooded by water from upstairs in the event the main line becomes blocked. This is because water can only flow in one direction due to the internal design of the valve. The flapper inside the valve remains closed by default. This is where the name nromally closed comes from.

Normally closed backwater valves protect from a situation where your main drain becomes plugged. If you continue to use your upstairs fixtures like your toilet or sink it will not be able to drain out of your main and will find the path of least resistance. This could mean travelling back up the line and out of your basement toilet, sink or shower drain. With the backwater valve in place the water will be unable to travel up the line preventing flooding.

Canadian Code for Normally Closed Backwater Valves

In the scenario depicted above you would not be allowed to place any Y takeoffs to the left of the backwater valve. This is because the backwater valve needs to isolate the downstairs takeoff to prevent flooding.

Current code stipulates that any fixture below grade needs to be protected by its own backwater valve. Below grade basically means in your basement, so this is of particular importance in Winnipeg where the majority of homes have basements. This requirement came into effect around the year 2000 in Winnipeg so if your house was built after that there is a good chance it contains normally closed backwater valves.

It is particularly important to protect basements from this type of backup because sometimes these types of blockages go unnoticed. We have had customers in Winnipeg who have flooded their own basements and then call us after they notice a smell coming from their basement and realize that dirty water has been coming out of their basement drains. 

While normally closed backwater valves are required to be installed in new homes they can be difficult to install in older homes because the plumbing is generally buried under the floor. In this situation your next best bet is to install a normally open backwater valve.

Normally Open Backwater Valves

Normally open backwater valves sit on your main plumbing line and protect from sewer backups from the city. They are sometimes called main line backwater valves. In the case of a city sewer backup the flap inside the normally open backwater valve is triggered and closes, protecting your home from flooding.

These types of drains are particularly important in older areas of Winnipeg like St. James, City Centre, St. Boniface and Fort Rouge that still have combined sewer systems. While these sewers are no longer built they still exist in many older neighbourhoods. A combined sewer system is when wastewater and rainwater drain into the same system. During a large rainfall event these sewers can become overwhelmed leading to sewer backups and flooded basements. 

Normally open backwater valves are easier to install than normally closed backwater valves as they are found on your main plumbing line. This is generally easy to locate in order to install a backwater valve.

Visual Explanation of Backwater Valves

Contact Us for More Information

If you are concerned about backwater valves in your home it is best to call a licensed plumber to come and check your home’s wastewater plumbing system. At Next-Gen Plumbing and Heating we are backwater valve pros. We have helped many Manitobans to locate and install backwater valves in their homes. If you would like more information please contact us. We are always here and happy to help. Thanks Manitoba!