Background: Our 25 year old, rarely used, tile shower is located on the first floor of our SoCal home. There is no basement. When the shower is used the water flows into the attached garage (shared wall). There is rust around the pipe under the drain and two holes in the pipe just above where it seems to attach to a rubber gasket/flange which then goes into a black plastic pipe. One of the holes seems machine cut (? For air exchange) the smaller hole I believe is corrosion. From my testing the leaking doesn't happen when I have poured large volumes of water into the pipe through a funnel thereby bypassing that corroded area.

How can this be corrected? I see that the Wingtite Shower Drain replacement kit is for fiberglass showers. Two plumber have talked about tearing up the entire shower and we need to avoid that large expense if at all possible.

Is there any accses to get under the shower?By tile shower do you mean it's a home made shower floor that has the drain just cemented in ? Im trying to get a visual on this but need more details if I can help, Bob or Tom are you guys around, this looks like something you gentelmen can help with also.There must be some sort of acces to the plumbing to fix this problem, unless like I was thinking it was a home made desine(sp).

Pete got you started with some good questions. Chances are pretty good than shower pan must come out if its on a slab and you have a mudd pan. Tell us more about the pan/floor, what's it made from. There should be no holes in that pipe, I'm guessing it's a 2" black pipe, maybe galvanized and the finish is gone. When Pete said home made design shower he is describing a custom mudd pan build on the slab and then covered with ceramic tile, that what you have?