how to install drain for fiberglass shower?

Old 04-05-06, 11:19 AM
Thread Starter
Join Date: Apr 2006
Posts: 24
Upvotes: 0
Received 0 Upvotes on 0 Posts
how to install drain for fiberglass shower?

Hi. I've done a lot of plumbing, but not this one and it has me stumped!

I have a one-piece fiberglass shower unit that I am installing in a new bathroom in a basement I'm finishing. I have rough-in plumbing that provides a 2" PVC drain pipe sticking up several inches through the slab (I have confirmed that it is trapped so no problems there). I have a two piece Plumbest plastic shower drain (D41-001). It consists of a piece that goes under the shower floor that glues onto the 2" drain line. It then has a piece that has a strainer attached with screws that screws down into the piece under the pan from inside the shower. In between the two are a rubber gasket and a cardboard friction gasket.

I am very familiar with gluing up pipe, but I'm not sure how this all works. I know I have to cut the pipe sticking out of the floor to the correct height. It appears that there is enough clearance with this particular shower unit that I do not have to chisel out any concrete around the drain pipe (is that a safe assumption? Or is there something I'm not realizing). I'm confused by the fact that it looks as though I have to be virtually exact on the height I cut down the pipe to, as the drain piece that glues onto it only has about a 1" sleeve length for the gluing surface.

Next, I'm not sure whether I glue the piece onto the pipe and then position the shower over it, or whether I attach the drain to the shower and then put glue on the pipe and set the whole thing in place over the pipe. If so, that's where I'm really nervous as it is obvious that I only get one shot at this and everything has to be just right.

Finally, I have no idea how the gaskets play in all this and which go where. Do I use any other putties or materials? I just love how the shower unit instructions say, "Install drain per manufacturer's instructions". But, of course, the drain manufacturer provides no instructions!

Has anyone done this and know the procedure? I really appreciate any help.

Old 04-05-06, 04:06 PM
steve_gro's Avatar
Join Date: Jan 2004
Location: San Francisco
Posts: 967
Upvotes: 0
Received 1 Upvote on 1 Post
You may find it easier to use a compression drain. You attach it to the shower with a bead of silicon between the stall & the drain on top, gasket on the bottom.

You can then set the stall on the drain, mark it, remove the stall & cut (assuming you don't have an internal cutter to do it after the fact). Then tighten the castle nut in the drain.
Old 04-05-06, 05:24 PM
DaVeBoy's Avatar
Banned. Rule And/Or Policy Violation
Join Date: Mar 2006
Posts: 1,565
Upvotes: 0
Received 0 Upvotes on 0 Posts
Did you buy the stall from a Home Depot, Lowes or Menard's type home center? If so, or even if you didn't, I would actually go there and have someone show you how to pull this off. Yes, it can be tricky if you have never done this before, and you don't care to, or, accessing from below is impossible. I did several such stalls from 12-17 years ago (and haven't done one since) and I remember that it was like an I.Q. test. I remember muttering to myself how they should have been able to come up with a better method when people don't readily have access from below. But it can be done, with some kind of conventional shower drain.

It kind of seems to my memory that there is a drain that you can glue part of it to the pvc stubbed in pipe, at the right height of course, otherwise you will put pressure on your p-trap/waste arm coming away from it when you set the stall on top. The piece that you glue on to the vertical pvc under the stall is a female threaded piece (liek 3 1/2 or 4 inches in diameter). Once that is glued on, you place the rubber ring gasket ontop. Stick it there so it doesn't slip when you place the stall. Set the stall. If you did it right, the gasket should be either barely contacting the underside of the stall or be close to it. Then you take a male threaded half of the drain unit and put silicone caulk under it's flange. Then you might also want to put non-setting pipe dope on these male threads. Then screw the male threaded pvc fitting down through the shower hole. This will draw the female half and male half togerher, sandwiching the rubber gasket under the stall. Then screw on the chrome strainer. It's been years. But it seems to me that this is how I did these.

See if they don't sell such drain pieces for shower stalls at one of those home centers, that will allow you to pull it off, without needing access from below. The way I describe, you don't.

Last edited by DaVeBoy; 04-05-06 at 06:11 PM.

Thread Tools
Search this Thread
Ask a Question
Question Title: