Shower drain (25 years old) is leaking to basement below - water seems to be coming from edges of floor cutout and not directly down the outside of the ABS drain pipe itself (see photo). About 7 years ago, had same problem and seemed to resolve it by working from the floor in shower stall to (1) remove the top metal drain grate and then (2) apply silicone caulking under the "lip" of the circular rim of the plastic drain (see photo). It appeared there was old caulking there that had deteriorated - not sure if this would have been part of the original installation. I'm also not sure if there is a rubber gasket of some type under the top plastic drain that may be in need of replacement.
I'm trying to determine if the top white plastic drain can be screwed out to put in a new gasket and/or silicone caulking. As seen in the photo, there are 4 plastic "posts" protruding from the inside of the drain piece and wondering if these are indended to be used with pliers, or some special tool(?? ), to unscrew the piece. The tile floor is ceramic tile so I'm not sure if the tile and grout might prevent the drain from being unscrewed (if it is intended to be unscrewed).
I'd appreciate any advice you can provide on how the drain piece might have been installed (screw-in, gasket, caulking, etc) and what suggestions you have on trying to eliminate the leaking.
Thanks, Brad

Hi Brad...

The strainer assembly screws in for sure, but that isn't going to be the problem here.

The problem looks to be a problem with the vinyl liner and the drain connection. In order to fix this you will probably need to remove some of the tile and cement from around the drain assembly, WITHOUT damaging the vinyl liner, and see if you can reseal the connection between the vinyl liner and the reversible clamping ring and drain base (see image).

I have attached a picture of a vinyl liner shower strainer assembly so you can understand what I am talking about.

Also, you could have another issue such as water getting behind the tiles of the tile wall and water is showing up at the drain area... could be? Here, be sure all the tile is grouted well to help eliminate this as an issue.

Be sure to check the plumbing behind the wall as well... depending on how the pipes are run upstairs, a leak at the valve or shower head could also show up at the drain.

It could also be an issue such as a hole in the liner and if that is the case, this shower pan is shot and will need to be ripped out and replaced.

Hope that covered the basics here...

Questions? Let me know, OK?

Mark