BuckeyeBBQ
New Member
I'm currently replacing a fiberglass shower insert with a tiled shower. In preparation, I've done some demolition and need to move the vent pipe from the shower drain, in order to lengthen the shower by approx. 18". The vent currently runs up the far end wall of the shower. I expected to find it running laterally up in the ceiling area and connecting to other vent pipes running up through the roof stack. What I found is the shower vent stack pipe runs up and then crosses over and connects to the vent pipe coming off of the adjacent whirlpool tub. Neither vent pipe appears to be connected to a common stack somewhere above. Is this an allowable way to plumb adjacent vent stacks? I've read many posts here on proper venting distances, etc. and for the life of me I can't understand how this current setup could be correct or within code? I can see how the vents would each be able to pull air from the adjacent drain piping as long as they weren't liquid full, and we've had no discernible problems with draining, traps being dry or sewer odors from the drains. I've attached a diagram to illustrate the connections. I'd like to correct it now by finding the closest real vent stack connection if that's how it should have been plumbed in the first place.