A backwater valve, also known as a sewer backup or back-flow valve is a valve that you can install on your sewer line to allow water or sewage to flow in only one direction. That is, away from your house. Whenever there is a severe and sudden downpour of heavy rainfall, the city sewer lines sometimes become overwhelmed causing either sewage or water to flow back into your home. A backwater valve and a sewer system backup, if installed in your home will prevent any back-flow into your house.
A backwater valve can be included during the initial construction of your house or it can be retrofitted later. Some municipalities require that a backwater valve is installed in every home while others recommend it. Installing during initial construction can cost about $150 to $250 while retrofitting can range from $1,000 to $2000 because some concrete will probably need to be removed from the main sewer line. Some municipalities offer subsidies to assist with the installation of backwater valves.
How does a backwater valve work?
Your home’s sewer system works by allowing water and sewage to flow away from your house. However, in some cases, there may be a backup in the main sewer line overloading it. A backwater valve will prevent any water or sewage from flowing back into your house. You can check if your installed backwater valve is working properly by looking through the clear cover of its access box.
The valve has a small flap inside it that is usually open allowing water to flow away from your home. It also allows the venting of any sewer gases. On each side of the flap is a flotation device. If there is any back-flow of water, these floaters cause the flap to lift up and close, preventing anything from flowing back into your house.
For a backwater valve that is being retrofitted into an already constructed house, the owner will need to obtain a plumbing permit from the municipality. A plumber, who is both qualified and licensed will cut a hole in the concrete floor near the floor drain. Backwater valves usually have a clear top so you can see if it is operating properly.
Backwater valve maintenance
If your backwater valve is properly maintained, you should not experience any problems. Maintenance of the valve includes regular cleaning and removing any stuck materials. You can have a plumber do this for you but you can also find several do-it-yourself instructional videos online that you can easily follow.
If by any chance the main sewer line becomes overloaded, you will be safe from any back-flow of water or sewage. However, this also means that anything coming from your house will not be able to flow out because the valve will be closed. Your plumbing system has a certain amount of storage space to account for this but you may want to avoid running your shower, washing machine or dishwasher all at once during a major rain storm or when snow is melting outside. You may end up flooding your own house if you did this because there wouldn’t be an outlet.