The humble plumbing vent is something most homeowners never think about — or weren’t even aware of in the first place. Here’s what you need to know about this crucial part of your indoor plumbing system.
What is a Plumbing Vent?
If you look on your roof, you’ll see a pipe sticking out of it, typically with a vent cap on top. This is your plumbing vent and it’s crucial for the function and safety of your plumbing system.
How Does It Help?
The plumbing vent allows air into the system each time you take a shower or flush a toilet. This air balances the air pressure.
The most important thing a plumbing vent does is to keep the water seals intact in your plumbing traps (or p-traps). An intact water seal keeps sewage air from entering your home through your plumbing fixtures.
Your plumbing vent also allows fresh air into the system, which helps facilitate water flow and drainage.
Hammerpedia notes that a plumbing vent also has several secondary benefits (and his diagrams are great, too):
- Better drain flow
- Less drain noise
- Sewer gas transported outside
- Public sewer vented
- Primary septic tank chamber vented
What Happens If The Air Pressure In Your Plumbing Isn’t Balanced?
If you don’t have proper venting in your plumbing system, sewage gas can leach into your home, making it smelly and potentially dangerous. Hydrogen sulfide, the gas that makes a sewer smell like rotten eggs, is not dangerous at low levels but can be toxic in high concentrations.
If you don’t have a functioning plumbing vent or if the one you have is blocked, pressure will build up in your drainage pipes. This can cause:
- A sewage smell
- Standing water due to slow drainage
- Bubbling or gurgling sounds in your pipes
- Problems with water flow
If you’re having any of these problems, be sure you contact a certified professional plumber so they can fix it.
Sources:
Plumbing Vents (The Ultimate Guide)
Plumbing Vents, Why Houses Need Them (forget the water bottle analogy)
What Is A Plumbing Vent And What Does It Do?