We are installing a new shower in the first floor bath and there is no vent for the drain. We live in a three story 106 year old story house. All three floors are finished. Venting to the roof is not an option. What can we do?

Lot of typing to explain this, if no one else gets it I will type it out when I have more time.

Hopefully, the lavatory has a vent. If you route the shower drain to the lavatory drain, it might be wet vented by the lavatory vent. It depends on the distance and the pipe diameter. How far apart are the fixtures?

From pm: "Thank you for your response. The fixtures are 7' apart but are on opposite sides of the room. Using 1 1/2" pipe."

Please respond on the board so others can see and help!

I think 7' is too far. Also, if there is no tub with the shower, the drain has to be 2" pipe. Speedball1 or doug can probably explain the maximum distances for each pipe size.

I'd appreciate whatever suggestions anyone can offer concerning this.