Are air admittance valves allowed in the main drain pipe like this?
Home is only 5 yrs old. Kitchen has AAV installed correctly but this one for the tub just seems like a potential for sewer leakage in the event of a backup!
Thanks in advance for the help
John
John
It seems to be o.k. there, but here is some more info.
http://www.toolbase.org/pdf/techinv/aavs_techspec.pdf
Access: That which enables a fixture, appliance equipment, fitting, or pipe to be reached by ready access or by a means that first requires the removal or movement of panel, door or similar obstruction.
Crawl space does not meet this standard, basement may
Location: The air admittance valve shall be located within the maximum developed length permitted for the vent. The air admittance valve shall be installed at least six (6) inches above the flood rim of the fixture served.
Below the tub/fixture does not meet this standard
I’d call this install out and let them that want to argue consult the AHJ for a final ruling
Hi John
Here is the actual code.
**3114.4 Location
**Individual and branch air admittance valves shall be located a minimum of 4 inches (102 mm) above the horizontal branch drain or fixture drain being vented. Stack-type air admittance valves shall be located a minimum of 6 inches (152 mm) above the flood level rim of the highest fixture being vented. The air admittance valve shall be located within the maximum developed length permitted for the vent. The air admittance valve shall be installed a minimum of 6 inches (152 mm) above insulation materials installed in attics.
http://www.studor.com/codes.htm
Thanks for the help guys, I called it an untypical installation and review by a Qualified Plumber is recommended.
Thanks again
John
