Badly designed Oatey Shower Drain?

I'm really upset and could use some advice. So I had a plumber do the rough plumbing for a bathroom I'm adding to an existing bedroom. They used an Oatey brand shower drain made for tiling over a membrane. I need to put down floor mix for a pre-pan. The way this drain is designed there is no height at the drain to allow for a layer of floormix. In addition, there are no counter-sunk holes for the screws leaving the screw heads sticking up. I don't like the idea of the rubber shower membrane sitting on top of those screw heads. What a piss poor design.

I'm tempted to tear it out and replace it with a proper drain but the second problem is the vertical pvc that comes from the trap up to the drain has couplers in it and there isn't enough 2" pvc where I could cut it and put a new coupler in place. I did see a youtube video where they showed you could put glue on the inside of the pvc and light it on fire and then break the bond and pull the pvc out of the coupler but I really, really do not like the idea of reusing anything that was previously glued before. Moreover, there is sewer gas in that line since its never had water in the trap.

What are your thoughts?

Those 4 phillip's head screws do not look like they belong. I'd recommend calling the plumber back and have him explain why he did what he did.

You said those screws look like they don't belong there but actually the drain has to be fastened to the sub floor and there is no other way to do it. Its just a really badly designed drain.

I ended up cutting the drain and removing the sub floor so that I can get at the PVC and install a proper drain. As you can see from the photo, there are a lot of couplers in the run. That was all me as I had to redo some badly done work on the sub floor and I reused the drain before I realized I should have thrown it away to begin with.

I think I can do one of two things. I can either use a PVC wire saw and cut out that coupler at the bottom and hope that I have enough stub sticking up to put in a new coupler and then run a new stub of PVC up to a new drain, or....I believe they make a coupler that would slip inside the 2" stub that's there and the other end would accept a 2" pipe, correct? I know for the drain its not the best idea to reduce it internally below 2" but if I can't get a coupler in there what else can I do?

when I install/set drain I taper cut the plywood so the flange is flush with the plywood. no screw needed. take them out. float a sloping mud base from drain to perimeter. flush at drain and just barely enough slope so water will drain to flange. the membrane will go on top of this. seal the underside of membrane to the flange with silicone. Then the upper half of flange gets bolted down over the membrane. The upper part sometimes a 2 parts. 2 part upper so you can adjust finished height of drain for mortar and tile.

You don't need to screw drain down. once the membrane / upper flange / tile is installed that drain is not going to move.

Just cut below bottom coupling. If using a brass drain make the tail pc with pvc and proper adapter to brass/cast iron drain assembly. lay down a new subfloor sheet. start with a small hole. make the tail piece just a bit longer than you need with an un glued coupling stick it back onto the piece still in the p-trap. now trace out the out line of the drains bottom flange. trim the hole in the wood carefully. Taper the hole so the flange can NOT fall through but sets flush with surface. make sure the bottom of p-trap is supported so when you are ready to make the final glue joint on coupling , the trap cannot push down when you push it together. you previously made the tail piece a bit to long. make sure you trim it and allow for coupling.

here is a good video of installing the mortar and membrane. As previously stated you can forgo cutting hole in floor with taper and just make hole big enough to drop in drain and have it sit on floor . method in video will float mortar up flush with first flange. make more scince. hey way I previously described was how I was taught. paper first looks like better install. expanded wire might be over kill on first layer. lots of videos on youtube .

Install mud base and membrane in tiled shower pan

Mr_David said:

here is a good video of installing the mortar and membrane. As previously stated you can forgo cutting hole in floor with taper and just make hole big enough to drop in drain and have it sit on floor . method in video will float mortar up flush with first flange. make more scince. hey way I previously described was how I was taught. paper first looks like better install. expanded wire might be over kill on first layer. lots of videos on youtube .

Install mud base and membrane in tiled shower pan

Click to expand...

Thanks. The new drain I purchased has no taper. It sits flat on the sub floor.

I split the bottom couper and used heat to peel it off. I cleaned up the pvc stub with emory cloth, primed it twice to soften the old glue and then I installed a new slip coupler instead of a DWV coupler. The slip coupler slid on further than the DWV and got on clean PVC. I'm confident this will never leak.

Good idea about supporting the trap before gluing on the vertical PVC and drain. I will do that.


That video had a couple of things I hadn't seen before like using tar paper behind the durock instead of plastic and putting the pebbles by the weep holes in the drain.

One thing I think may have been wrong in the video though is putting up the durock before pouring the final base. I would have thought the base is poured and then install durock holding it up a 1/4" or so off of the base so that it has no contact with the base -- to prevent wicking water into the durock. Then fill that gap with silicone.

MNBobcat said:

One thing I think may have been wrong in the video though is putting up the durock before pouring the final base. I would have thought the base is poured and then install durock holding it up a 1/4" or so off of the base so that it has no contact with the base -- to prevent wicking water into the durock. Then fill that gap with silicone.

Click to expand...

That seemed to be a good idea at first thought but if any moisture gets past the tile on wall you don't want a silicon barrier preventing moister from finding it's way down to the water proof membrane and on to the drain.
I was curious. I am not an expert on tiled showers so I started looking for more information. Found a another interesting video. Guy talks about not using plastic or tar paper behind Durock because it can cause mold to occur and he also puts Durock on wall before tile mud base. Not to thrilled about how he did the membrane at top edge of dam but again I'm not the expert.

Lots of good videos out there . just have to weed through them and take the best from each and run with it

post up some pictures of your progress . would like to see how it turns out.