Originally Posted by
atticguy
hey tom, how goes it?
i just completed my cast to pvc conversion of my attic reomodel. i did revent all my existing fixtures up so that they are 6" above the flood rim of my 2nd floor lav. my question is why? :confused: i can't seem to come up with a decent reason. could you enlighten me? also, i plan on using a studor vent on my attic lav, and from applications i heve seen, they are installed only a minimum of 6 inches above the tee. what gives?
to sum up:
1)why do the fixtures have to be revented 6 inches above flood rim of highest fixture?
2)why doesn't this apply if i use a studor vent on that highest fixture?
thanks again for all of you professional advise.
louie
Good morning Louie, Welcome back, How did your attic installation go? I still have the diagrams that you sent me on file.
I'll answer your questions in order.
(1) )why do the fixtures have to be revented 6 inches above flood rim of highest fixture?
Because Chapter 14,(Vents and Venting) Section 1406.3(Height above fixtures) of The Standard Plumbing Code says so. And Studor AAV manufacture agrees with them in their installation specs.
(2)why doesn't this apply if I use a studor vent on that highest fixture? Where did you get this information from? It applies to all installations,
(3)i plan on using a studor vent on my attic lav, and from applications I heve seen, they are installed only a minimum of 6 inches above the tee. What gives? That's the MINIMUM of 6 inches, the maximum can be as high as you wish. Where did you wish to install it?
Plumbing codes are written to address the worst possible scenario. Lay it out on paper, if you left a open vent or revent below the water level in a fixture and since water will seek its own level you will get a backflow into the vent system.
Good luck Louie and don't be such a strainger. Tom