Re: Back venting
Posted by Steve on September 06, 2001 at 21:26:41:
In response to Re: Back venting
: : I need to hook up 2 sinks ( 1 gal/min max each) on the same wall on the same floor. Do I need 2 vertical back vents @ 1 1/2" or will 1 do? If I vent up from sink 2 it is 12 feet to the main 3" roof vent. There are no fixtures above these. Check my drawing. Thanks, and congratulations on a great site.

: My drawing is at

Im not positive on this but I think on 1 1\2 pipe (drain) you can't be more than 5 feet from the stack without back venting and on 2 inch I think it's 8 feet. can't u just circuit vent it, on the farthest one 90 over at 42 inches above the floor and catch the nearest one with a san-tee then tee into the stack. But one thing u might want to think about is at 12 feet from the stack you will need to keep your grade at 1\8 inch per foot because you can't drop down on a run ( I think) more than the pipe size. in other words on a 2 inch drain arm, the max would be 8 ft. at a 1\4 inch per foot because 8\4's is 2 inches and on 1 1\2 pipe it would be 6 ft. at 1/4 inch per ft.

Replies to this post
There are none.