Bad weather or a clogged sewer can risk your basement experiencing backwater. Normal plumbing happens when waste water flows from the home to the city sewer.
While sewer backflow occurs in the complete reverse. That's a big no-no!
Think about the contaminated waste that could enter your home. This can pose a serious health risk and property damage that could have been avoided with proper building and plumbing design.
To be better off safe than sorry, installing a backwater valve or sewer backflow preventer is necessary. Find out how sewer backflow valves work in this comprehensive article. Read on.
What Is a Backwater Valve?
A backwater valve is also called a sewer backflow preventer or a sewer backup valve. This tool is installed in your sewer line to allow water or sewage to flow in only one direction: out of your house.
A backwater valve is especially useful when heavy rainfall or snow melt causes city sewer lines to experience increased water pressures.
These events prevent sewage from flowing smoothly. Backwater valves are worth the investment, especially when you have a basement.
There is a higher risk of water backup when your house is mounted less than 30 cm above street level. If this is the case, The National Plumbing Code will require you to have a backwater valve.
Even so, these valves are required and recommended by many municipalities. Some municipalities will offer subsidies to aid homeowners with the costs of installation.
A sewer backflow preventer can either be installed during initial construction or retrofitted in existing structures.
Installing them while in construction will cost less at just around $500, while retrofitting them will cost around $2,000 to $5,000. The higher cost is due to the need to remove certain foundations to access the main sewer line.
How Does a Backwater Valve Work?
When the city sewer or municipal drainage system overflows, this sends waste water from the sewage pipe to your home sewage system.
When this occurs, your sewer check valve detects it with a floating gadget.
It then closes its flaps automatically. Its flaps only reopen once the water level is back to normal.
This simple mechanism operates without the need for electricity, making it easy to maintain and effective even during power outages.
Why Is a Sewer Backflow Preventer Important?
A backwater valve protects your water system, especially your drinking water supply, from sewage backflow and rainwater when the municipal drainage system is overworked.
It is crucial in any home for the sake of sanitation and health.
Sewage entering your home can carry E. Coli, hepatitis, and Leptospirosis. You can get diarrhea, muscle pain, stomach cramps, liver infections, and nausea.
A specialized backflow preventer also avoids unnecessary expensive repairs; in any case, your property gets damaged.
When a home is flooded by sewage backflow, you will need to clean your home deep. In worse cases, the walls and flooring may need to be replaced.
If you don't do this, mold can form in less than 24 hours. This can cause allergies, asthma, and other chronic respiratory disorders.
With that, it's no question how extremely important you get a backwater valve installed!
How to Maintain a Backflow Preventer
Every specialized backflow preventer has internal seals, springs, and other moving parts. All of these are subject to your typical plumbing system deterioration with time.
To ensure your backwater valves will work when you need them the most, periodic maintenance is necessary.
When not used for a long time, the gate valve can become stuck in an open position and possibly be blocked. Remove any debris that clogs the valve and test whether moving parts can move freely.
One way of doing it yourself is to run hot soapy water through the sink to clean the system fairly. A long-handled brush can be handy when you scrub around the flaps too.
Make sure to wear rubber gloves, so you don't get exposed to contaminated water.
You’ll also want to look at the O-ring around the lid of your sewer backflow preventer and the floats on each side of the flap. If they are worn, replace these parts.
If you're unsure whether your sewer backflow valve is in good condition, best call a plumber to inspect and make the necessary repairs.
Types of Sewer Backwater Valves
There are multiple types of backwater valves.
They will vary in price, installation, and effectiveness. It is important to consider them carefully before installing them to avoid unnecessary costs.
Here are the different types of backflow valves and their attributes:
Sewer Check Valve
When a public sewer backup recedes, the sewer check valve will excrete waste water out to the public sewer.
This type of sewer backflow valve is perhaps the most affordable and commonly installed.
A check valve will not prevent backwater 100%. Thus, this sewer backflow valve is only best as a short-term backup. It still needs to be maintained annually for a smooth operation.
Automatic Flood Gate Valve
An automatic flood gate valve functions on air pressure. It closes automatically with the help of its stainless steel knife edge when backwater is suspected.
An automatic flood gate valve is 100% effective in stopping wastewater from entering your home and causing damage.
It is the most sophisticated among specialized plumbing devices.
It also has a larger valve due to its air chamber. Thus, it must be installed only by licensed plumbers who can follow manufacturers' instructions.
Manual Sewer Gate Valve
As its name implies, a manual sewer gate valve must be opened and closed manually. That means you have to anticipate when the water pressure arises and recedes.
Although a manual sewer valve is dependable, it still has a great chance of backwater damage occurring due to its lack of automation.
Air Gap Backflow Preventer
An air gap backflow preventer is a simple yet reliable device for preventing backflow.
Its system involves an air gap or an unobstructed vertical space between a device, such as a faucet or a valve that connects to a plumbing system.
An example is the open space between a water outlet and the floor level of a kitchen sink. There are no moving parts except the flowing water supply in an air gap.
Depending on the plumbing fixtures used, many plumbing codes will specify the minimum air gap distance.
Specialized Backflow Preventer
When a specialized backflow preventer is preferred, it also must meet the plumbing code and require a licensed plumber to install it.
It is commonly installed near a residential water meter right after the shut-off valve.
Some specialized backflow preventer models include an RP (Reduced Principle), PVB (Pressure Vacuum Breaker Assembly), DV (Double Check Valve Assembly), and RDC (Residential Dual Check Valve).
These valves are used when there is insufficient vertical space for an air gap.
How to Have a Backwater Valve Installed
Before having your backflow valve installed, make sure to do the following:
- Check with your local authorities whether you need a plumbing permit and other necessary building permits.
- Check whether your downspouts and drains are not connected to the sanitary sewer or weeping tiles. When you need to disconnect the foundation drain, a sump pit and pump will be required.
- A professional plumber must be hired. Some municipalities will keep a list of approved plumbers to do the job.
- Check ahead what specialized tools your backflow prevention device requires. Have them ready by your hired licensed plumber for a swift installation. Some parts may even need fabrication or be purchased directly from the manufacturer.
Sewage starts to backflow often through the floor drain, sink, tub, or toilet.
A professional plumber will need to cut a hole in the concrete floor near the floor drain to dig down the main sewage line to install a new valve.
A sewer backflow valve is often installed in the main sewer pipe outside of your home or in the basement. Ideally, it should be located at the farthest exit point and installed downstream.
This is necessary to prevent sewage and wastewater from flowing into your sewer pipe and your device.
Installation and maintenance of a backflow preventer, as well as sewer line repair, can be complex.
It might need the use of specialized plumbing tools. These include pipe cutters, pipe extractors, a line pressure gauge setup, and brass and plastic adapter sets.
The installation will vary per manufacturer. But the commonly used methods are the "Threaded and Glued method," which involves using a threaded T device into the pipe, and the "Compression Fitting method," which relies on a pressure washer sealing the pipes.
Installation Issues
- If your house sewer also accepts rainwater flow from the roof or area drains, installing a sewer backwater valve may not be efficient.
- You should not install a sewer backwater valve on the house side of the trap. If it leaks or blows off, your home will be flooded with wastewater.
- The sewer backflow valve cannot operate properly if there is a low pitch on the pipe. Your drain might frequently clog too. You might want to learn how to fix a clogged sewer line.
- If improperly installed, your drinking water will pose health risks. Wastewater carries a multitude of germs, viruses, and bacteria. Costs for a clean-up and testing may even exceed your costs for installing your sewer backflow valve. Your backwater valve should ideally be installed at the front of your structure where the sewer lateral enters the foundation wall.
Sewage Backflow Causes
Sewage backflow is caused by back pressure. This is the reduction in water pressure in one portion of the sewer system, causing the water in other surrounding areas to flow backward.
If you suspect your sewer line is collapsed or obstructed, it is important to check for signs such as gurgling noises, slow draining, and water backups.
Sewer backflow is caused by different situations, including:
- Public blockages caused by tree roots in the sewer line, construction mishaps, or plumbing system deterioration
- Private blockages in your office's or home's own plumbing system (bellies in your sewer lines like the failed sump pump, hair clogs, grease clogs, and physical obstruction caused by napkins, diapers, cigarette butts, toilet paper, etc.)
- Insufficient capacity due to the increased number of residents in the area
- Cracks in the pipe
- A back-pitched drain system
- Sewer system surcharges due to heavy rain and snow melt
Frequently Asked Questions (FAQs)
Got more questions about sewer backflow preventers? We've got you covered!
In most cases, a sewer backflow preventer is necessary for efficient flow in your plumbing lines. Your own plumbing system should be one of your top priorities when building any home or structure.
Plumbing is an essential aspect, especially during the planning stage of your construction. It assures your property is safe from damage and the health hazards of bad plumbing.
With proper and regular maintenance, your backwater valve should last many years.
Make sure to follow the manufacturer’s recommendations which usually involve regular cleaning and repairs.
Keeping your valves free of unnecessary materials will also help extend their life expectancy.
Conclusion
There are no doubt sewer backflow preventers. They are essential in any sewer system. When bad weather occurs or even when obstructions arise, you'll have them to thank!
Avoid getting sick from wastewater contaminants and spending good money on property damages. Get your sewer backflow preventer installed today!
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