View Full Version : Can I change location of vent connection?

05-07-2011, 11:28 PM
I 'd like to move the T-connection at B to location C. This move would result in distance A (=the 90 bend to the p-trap connection) going from about 50" to about 12".

I can't think of a reason why I can't do this, but then that kind of thinking has got me trouble before...

Thanks a lot for any advice.

05-08-2011, 01:46 AM
The horizontal section of the vent needs to be 6" above any flood level.


05-08-2011, 07:14 AM
Distance "A" has nothing to do with anything. But, your connection "C" MUST be 6" above the overflow line of the fixtures AND/OR 42" above the floor, whichever is LOWEST. Your "point C" does not conform to either requirement, but "B" probably does.

05-08-2011, 11:32 PM
Thanks both. Looks like point "C" is out of the running. Glad I asked.

05-09-2011, 05:40 AM
What were you trying to accomplish by moving it?

05-09-2011, 11:15 PM
It's a bit of a long story but to cut to the chase, we're installing a shower and the shower doors are going to need some wood to screw into. The vertical part of the vent (A) is right in the way of us sistering a stud to an adjacent stud. The sistered stud would provide the base for the shower door. So, I thought if I could move the assembly down a bit (reducing A) , I could sister part of a stud above the vent and then sister another against that, that would reach the bottom plate. (Forming a kind of a stud bridge over the relocated vent). That's kind of hard to describe....

If I did that though the new vent connection would be below the drain holes of the bathroom sinks, thus violating your specs.

But, with a bit more work, I think I can just move the whole shooting match to the right without changing any heights of connections. The vertical 'culprit' part of the vent would then be out of the way. Thanks for any further hints.

05-10-2011, 05:41 AM
The door is held by three screws, so you could just insert three 1x4 crosspieces where the screws go. You do not need a 2x4 to screw into. In fact, if you have a mudbase tile job, you do not even need wood in most cases, especially if the door has a header over it.

05-11-2011, 05:09 PM
Thanks again. I will consider the cross-piece idea and see I can make it work.
Failing that, is it acceptable (while not necessarily aesthetic) to have the vent go from B horizontally to the right but a shorter distance than present, then down vertically and then horizontally to join the system at the bottom arrowhead of length A? (It would form a vertical "Z"). The idea is to move the original vertical section of the vent to the left (i.e. in the next stud bay to the left) and away from the door area. I appreciate your help.

05-11-2011, 05:49 PM
You can move it over using 45 degree bends. The vent cannot run at less than 45 degrees anywhere below your point "B"

05-12-2011, 12:45 AM
Thanks cacher_chick. I think that will let me get back to my normal life again, if I can remember what it was... I appreciate everyone's help.

05-12-2011, 05:45 PM
One last question. To use cacher-chick's 45-degree solution, I'll have to lower the shower drain connection (the one just below the lower arrowhead on length "A") towards the main ("WASTE") pipe.
Is there a minimum distance I need to keep between the shower drain connection and the main waste pipe? Thanks very much.

05-12-2011, 08:48 PM
I'm not clear on what you are trying to do.

The trap arm to the vent needs to be maintained at 1/4" per foot pitch. The length of the drain pipe AFTER the vent is not limited.

05-13-2011, 12:25 AM
The second component of your answer answers my question. Thanks very much ! Have a great weekend.