Without gurgling or fumes, drain-waste-vent pipes (DWV), carry water and waste out of your house. This requires an air passageway behind water. Vent pipes run from the drain pipes through the roof and provide air passageway. They also carry odors out the house. When you are planning to install a new appliance, or add on to your existing system, it is important that you know how the drain will be vented. It’s not always easy to find the right solution. There are many venting options available when designing a plumbing system plan. Each type can present challenges or complications. Below are details about each type of drain vent to help you plan your remodel. Before you finalize a plan, ensure that the venting scheme has been approved by a local plumber inspector.
A code may allow a wet vent if a fixture is too close to a stack. If a tub is located close to a stack, the drain can be emptied into a pipe that serves as a vent.
A loop vent might be allowed for a freestanding sink. You might need to vent through the roof if you have difficulty resolving and are not allowed to wet vent.
A vacuum valve (AAV), which opens to allow air in to drain waste, is then closed by gravity to prevent sewer gasses from returning into the room. These relatively new devices can be used to replace vent lines in many areas. AAVs can vent multiple fixtures depending on their size and code restrictions. Make sure to check the codes for AAVs.
It can be found in the basement or crawlspace directly below your home. It will most likely be cast iron, or in modern homes, PVC pipe. It is usually black. These pipes are usually at least 3 inches wide. Listen for the sound of a large draining sound when someone flushes the toilet.
An auxiliary vent is a vent pipe that attaches to the drainline near the fixture. It then runs up to the main vent. It can be attached directly to the fixture or to a horizontal drain line.
Two fixtures can be connected to the stack by a sanitary cross if they are located on opposite sides of a wall. This is known as a common vent. It can be used on sinks with back-to-back fixtures. A basement sink could be vented using a wall vent that simply runs out of the wall. A cheater vent, which draws air from the room instead of outside, may be permitted.
What Distance Should a Fixture be from a Vent Pipe?
If you are remodeling your plumbing system, do you need a wet vent or an older or separate vent? The answer to this question can be complicated because of the different formulae used. The critical distance (or how far a fixture can be from a vent pipe) is determined by three factors. These include the size of the pipe required by codes, the type and number of fixtures already wet vented along the same line, as well as the type of fixture. To determine if wet venting can be done, measure the length of your pipes carefully.
What You Need to Know About the Main Drain
To reduce the chance of clogs, plan drain lines. For bathroom sinks, 1 1/4 inches is the recommended size. Kitchen sinks are approximately 1 1/2 inches. These lead to the main stack which is typically 4 inches in diameter. The main stack is vertical and will not clog because it is horizontal.
Water flows downward through the stacks until it reaches the main drain line. This is an underground horizontal pipe that connects to either the municipal sewage system, or a septic tank. The main drain line might be made from clay pipe or another porous material in older homes. Sometimes tree roots can get into the main drain, causing water to back up into your home. A company that specializes is augering main line is the best solution.