Code On Bends In Vent Stack?

bob_cntrctr

Gentlemen,

Is what I found OK or do I need to get a plumber in?

Working on a two storey single family home with attic. Each fixture of the two second storey bathrooms (sinks & baths, not toilets) is vented straight up through the ceiling into the attic. The 3" ABS vent stack (yes I do mean the portion of the stack vent above all fixtures) goes up into the attic, where it turns horizontal, and takes four 90-degree turns (still horizontal) collecting the various individual vents that tee into it before turning vertically again and out the roof. That is, instead of the individual vents being routed to the vent stack, the vent stack crawls around inside the attic to them.

The horizontal run is properly sloped at 1/4" inch to 1/2" per foot. Total horizontal run is probably about 20 feet and is C-chaped (three sides of a rectangle).

It's the horizontal snaking of the main vent stack I'm unsure of. I've seen a single turn (two elbows) to shift a few feet over, but nothing like this before. I've also read all sorts of varying "opinions" about code limits on bends and/or horizontal runs, ranging from "must be a single straight vertical run but an inspector might overlook a single bend" to "as long as proper slope is respected any number of bends and any run is OK".

Anyone got the definitive so I can decide if I just ignore this or need to call someone?

Thanks.

Anti-wingnut

Sounds OK. It has been there for a long time, and has not caused any problems. To change it out would cost alot, be of dubious value, and penetrate the roof a number of times. You would be opening a can of worms. In my area, vent can be almost any length, as long as they are properly sloped toweards the fixture(s) they are servicing.

bob_cntrctr

Been waitin' to see if anyone else chimes in - but thanks for the info A-W.

Ron The Plumber

AW summed it up pretty much.