View Full Version : New Bathroom DWV rough in proposal

12-16-2012, 06:33 AM

1st post here. Looking to get some feedback about this possible DWV system for my bathroom renovation. Was going to wet vent the shower up the lavatory vent. and have 2" stack go to the attic. Shower drain line 2" will drain into the toilet drain line 3" but have a have the shower vent in line between the shower drain and toilet drain. Vent the the toilet up to the attic with 2" pipe and tie into the other vent before exiting the roof. Please post and potential problems you see here.

Also would a whole house AAV work instead of exiting through the roof.

Thanks in advance for your thoughts,

New Haven Ct


12-16-2012, 07:54 AM
Looks like you have it pretty well figured out. The shower and lav drains should be 2" and the weir of the shower's trap cannot be further from the lav drain than what is specified in your code. I would put a cleanout tee under the sink also.

The below-grade connections from vertical to horizontal must be done with wyes, not tees. The water closet bend will not likely be directly over the main drain, nor would I want it to be. You will have to work out the distance and angle to make the connection.

If I remember right, MA is one of those states where a homeowner is not allowed to do their own plumbing. This is a legal issue you should consider as doing a full bath without permits and inspection could wind up being a very expensive mistake.

12-16-2012, 08:02 AM
Any vent system needs at least one atmospheric venting point, so no, you cannot use an AAV for the whole house! Not sure if the wet venting of the shower will work well. The alternative might be to run a vent up that wall from the shower trap arm, then recombine them at 42" so you only need the one the rest of the way out.