Mar 22, 2025 · The AAV is to prevent the trap from siphoning out. You will need a new vent, such as an AAV, for the new standpipe trap. If you diagram what you will have, people could take a …

Apr 5, 2012 · The AAV is a one way valve letting air in to prevent siphonage, which BOTH traps need and your AAV will provide. The positive pressure situation occurs if the discharge is …

Dec 5, 2016 · An AAV ONLY allows air in, and if there is a positive pressure, which it can do nothing to eliminate, the drains will not function. Nope - just tested it as per Reach4's …

Apr 13, 2025 · Discussion on installing an air admittance valve (AAV) under a kitchen sink with an S-trap, addressing code compliance and practical considerations.

Feb 4, 2013 · An AAV only lets air in. With it in that location, when you flushed the toilet, there's a pressure wave in front of the wave as the stuff flows down the pipe. That would want to push …

Jan 24, 2025 · Yes for the IPC, although that requires you to get the exact slope of 1/4" per foot. Slope it more, you reduce the maximum horizontal. No for the UPC, as it further imposes a …

Dec 8, 2022 · An AAV only works with negative pressure, no positive pressures. A vent through the roof does both. In fact a vent through the roof is needed somewhere in the system for an …

Mar 18, 2024 · DIY plumbing a basement bathroom in Michigan (IPC) and am wondering about venting. Only real access to existing stack is a 3" line that carries waste from other bathrooms …

Aug 6, 2009 · Positive pressure with an AAV often occurs when there is a stoppage problem elsewhere in the system. Without proper diagnosis, you will try to get the sink flowing by …

Nov 23, 2021 · SFR in California, full kitchen remodel. The kitchen sink used to have a wall behind it that contained the vent line. New plan call for the sink to be on a peninsula, same …