Shower Drain Vent?

I am replacing the shower pan, which moves the drain 14†toward the corner (It’s a quarter-round showerpan). The main 3†copper vent pipe has a horizontal 30†long segment, which nearly crosses the shower drain’s vertical path. The nearest connected vent is the main, which attaches to the main horizontal slope (only 26†away from the new shower drain by straight line), but there is 64†(38†downstream and 26†upstream) to the vent. There is a separate roof vent for each of two lavatories. Do I need an additional vent for the shower drain? If so, can I use a Y-connection at the drain and connect it 4 feet above the drain to the main vent? I have access in the basement, where the drains are exposed, but the ceiling is plastered. I also have access above at the shower, where the floor is removed at the shower pan location. I should note that the trap for the shower drain is 2†below the main horizontal slope drain. I have pictures at www.photo.epson.com under the email address of jawx@comcast.net. Open the “Shower Drain†Album.

jawx said:

... 14†toward the corner .... Y-connection at the drain ....

Click to expand...

what length is the arm? the horizontal pipe going from shower trap to its first connection.

your description makse sense to you because you are there looking at each thing as you refer to it, but we cannot build that picture in our minds as you move about from the corner to up to down to sideways.

the link you provided goes to a hom epage and does not seem to lead me to a specific person's project. Post more.

david

Length of Arm

The arm is now 10" + 15" at 45 degrees to the main drain. As planned, the arm would be 8" +22" at 45 degrees to the main. It could be made longer or shorter. Since I am replacing copper with plastic, the trap is a little larger diameter.

Sorry about the pictures--they are essential to understanding my non-plumber's description! Go to www.photo.epson.com and enter my email address in the VISIT ALBUMS box (third box--not the sign-in email address box): jawx@comcast.net (write this down), then view the Shower Drain Album!