I'm putting in a 31" x 60" custom made cultured marble shower in my basement and I'm not sure how to hook up the drain. The shower base has a recessed hole for the drain assy. The pipe coming out of the floor is 2" PVC. The hole it comes up through is about 8" dia. And is filled with gravel. Can someone explain how to make the connection and or what type fittings I need? Also, do I use an adhesive like Liquid nails to hold the base in place?
Thanks,
Dave Ermeling

We set fabricated shower pans to the floor by placing baseball sized globs of modified thinset every 6" in all directions. Once that pans is down and cured it will never move or flex, no creaking sounds either. Most faricated pans have drain directions with them. Some provide you with a black ribbed collar that will slide over your 2" pipe to make a seal. Can you describe the opening in the shower floor, what came with the pan?

Hi Guys...

Dave, most likely you will need to purchase a brass NO-CALK drain (see picture below)... These are available at home depot or Lowe's. DO NOT purchase the plastic version of this drain. You should also pick up some clear silicone and some acetone or isopropyl alcohol for cleanup.

This drain installs super easy. Silicone goes under lip of the drain, rubber washer goes on the underside of shower base against the shower base and then the cardboard washer next and then brass nut gets installed and tightened to finish the drain assembly. Clean all excess silicone off unit now.. not later.

Now, prepare base area by using adhesive or modified thinset, OR if floor out of level may need to use a strong base of structolite perlited gypsum (sold at most home depots) to set the base in and level it with shims overnight (structolite dries overnight...modified thinset does not). Be clear here, however, that you need to refer to installation manual to know what is best to place this custom-made cultured marble pan in.

Then lower the pan over the pipe and level the pan in both directions (front to back and side to side)... like said above, may need to shim overnight.

Immediately after lowering the pan you will want to lightly soap up the inside of the black ribbed donut (see 2nd pic.) and slide down over the 2" pipe and push deep into the drain assembly. Then, lower the brass compression nut and spin in loosley.

Now you will need an inside pipe cutter (see 3rd pic... also sold at home depot).

Remove the brass compression nut you just spun in and then cut the pipe using the inside cutter drill bit to cut the pipe so it is about 1/4" above the rubber donut. This cut is critical and must be straight so practice cutting on a scrap piece of pipe in a vice or similar. The first few times I did this I cut the pipe to 1 inch or so above drain and then marked a line on the inside of pipe I was happy with... then followed the line and all was fine. Do not screw this up though and go below the rubber donut... ok?

After good cut is made you will install the compression nut and tighten it down with the slotted flat wrench that came with the strainer assembly... attach a string to this tool as it clumsy to work with and could fall down the pipe... ;) After that, snap strainer in place and you should be all done!

NOTE HERE that this is how I do all my drains for showers... but you never know... your custom one could be different... but I doubt it!!

Let us know if have any more questions...

MARK

Thanks for the great answers. Here are some pics of what I'm working with. So, I can set the pan in thinset or something with the pipe sticking up through the pan. Then after it's set up, I can use the Brass No-Caulk drain? Is there another way that doesn't require the critical cut of the pipe.Attachment 12098

Attachment 12099

Attachment 12100

Attachment 12101

Hi Dave...

You install the no-calk drain into the pan first... then set the pan into the mortar or structolite (I really think this stuff is best)... then install the donut from the no-calk drain.. then cut.

NO other way to do it except for the socket weld type strainer assembly (see picture)... but this also requires critical cut regarding height to cut... and when setting in mortar or structolite and leveling the shower base it is even harder than just using the no-calk drain.

This strainer assembly just gets cemented onto pipe.. then base gets lowered onto it and strainer screws into it.

Remove stones from around the drain and see if you can line that pipe up a little better.

I recommend the no-calk... ;)

Let me know if need more here...

MARK

Mark, I'll look for these items at Lowe's and Home Depot. The pan didn't come with any instructions. I had it measured and made at a local marble place. How much of the Structolite do I use? Do I notched trowel it on or just slap a thick layer down? I imagine the product will have some instructions.
I was told to install the base before drywall. The drywall will set on the lip of the pan and then I'll be putting marble walls on top of the drywall. Does this sound right?
Thanks again. Your answers are very good and clear. I appreciate the help.

So does the top brass piece compress the rubber donut? If so, what does it compress it onto? Or is it just a super tight watertight fit on the 2" pvc?

Hi Dave...

I determine the amount of structo-lite I need by dry-fitting the shower base. I have the no-calk drain in place then I lower it over the pipe then I use shims to approximate perfect level (front to back and side to side). Then I trace the placement of the level base onto studs of wall. Then I know exactly how much I need. Usually less than 1 full bag for 30"x60" base.

And yes.. the compression ring tightens down into threads and compresses the donut against the pipe and the sides/bottom of the strainer assembly.

If using structo-lite and it ends up getting between pipe and shower strainer you need to remove using screwdriver and cloth (I keep structo-lite about 6" from drain and then bunch squeezes over and fills void when setting pan)... then soap the inside of the rubber and slip down over pipe, etc...

If need more info. let me know...

Thanks Mark. It sounds easy enough. I will definitely let you know if I have any questions/concerns.

Dave

Mark, I didn't see the Structolite product or the inside pipe cutter at Home Depot? I'll check Lowe's. Is it a dry product in a bag or wet in a bucket? Is it in the flooring section do you think? I looked all over and the staff there were completely useless.

Hi Dave...

Structolite is a dry product sold in 50 or 80LB bags... see picture below.

It is a perlited gypsum basecoat for metal or wood lathe walls... then a veneer plaster is floated over to finish the wall. It should be near the dry bags of plaster or similar. Worst case, may need to find a plaster distributor in your area and purchase from them.

If no luck on the inside pipe cutter then pop by a local plumbing supply house... they will definitely have it.

Also, I noticed that at one of your last posts (post#6) that you mentioned drywall going on walls above the base... DO NOT USE DRYWALL... even moisture-resistant drywall in the shower area. Use 1/2" hardibacker cement board and alkali-resistant screws (green screws sold right next to the board) and plan on taping all seams (including corners) with alkali-resistant mesh tape and mudding the joints with thinset mortar. Keep cement board 1/4" off the base and fill this void with thinset as well (doesn't wick).

Keep me posted...

MARK

Thanks again Mark. The marble walls will not go all the way up to the drop ceiling so will the cement board finish smooth like the drywall? I think they just used drywall in our master bedroom shower? This basement shower will rarely see water too. Why the cement board?

Hi Dave:

I prefer to see cement board installed in place of drywall because drywall easily WICKS any moisture that may get between base and walls. Walls that wick moisture retain that moisture and mold/mildew can result.

Cement board isn't waterproof... but it does not wick/retain moisture anywhere nearly as fast drywall and is simply a longer lasting material that has a tenacious bonding ability when proper adhesives used!

At a minimum use the newer mold/mildew-resistant greenboard drywall (being sold at most home depots now).

If plasterer uses a proper bonding agent on the cement board above the wall panels prior to applying plaster then finsh will last as long as rest of bathroom. Be sure to use mildew-resistant primer and paint!

Whatever board is used, keep it off the base 1/4" and fill void with mastic or thinset mortar to help keep moisture away from board as much as possible.

Let me know your thoughts..

MARK

Mark, are you saying that instead of mudding and taping the cement board you use plaster? What adhesive do you recommend using to attach the marble walls to the cement board? Liquid nails?

I don't like mud in a bathroom... I plaster all my walls... but that doesn't mean you should!

Mud works great for lots of people if using mildew-resistant prime/paint and you have a FAN that is properly sized for the bathroom... ;)

100% silicone is best adhesive here. Of course, best really is to refer to the manufacturer's instructions... but you don't have them.. right? Apply as you would any adhesive and then apply panel to wall... then pull panel away from wall for 30 seconds and then reapply... sticks great this way.

These being cultured marble walls...I want to reverse my answer a bit....I think the mold/mildew-resistant greenboard will be best here...just keep it off the base 1/4 to 1/2"..ok?? The rest stands!!

Silicone to greenboard with cultured marble works great!!

Mark

Nope, no instructions from manuf.. I haven't bought the bathroom fan yet but plan on getting a good one with the most CFM and still quiet. I had planned on using the green drywall or even maybe the paperless.
Back to the shower base for a minute. The floor is pretty level so I shouldn't need a very thick layer of the Structo-lite. So just put it down about 1/2" thick covering the entire area covered by the shower pan but leave a few inches from the drain, right? Why do you recommend the silicone under the lip when using the No-Caulk drain? Just insurance against leakage?

No... silicone or plumber's putty MUST be used between the lip of a strainer and a shower base. I like the silicone in this case.. once sealed.. it's sealed.. and no bleeding/squishing of putty from under lip of strainer in future!

Structo-lite at about 1/2" to 1" thick... keep away from drain as discussed. Good luck!

MARK

Ok, Duh. You mean on the top side of the shower base. I gotcha. Thanks, a bunch.
Dave

Exactly! Thanks Dave.

Mark, I've got the base set. Darn that mortar is hard to mix. The pipe is centered well in the hole in the base. I don't care much for the way the pan was made. There's not much lip around the edges so if I put up backer board or drywall and then the marble walls, the walls will actually overhang the base. Not sure what I'm going to do about that. I'm going to try to go during lunch Monday to a local plumbing supplier to try to get the pipe cutter.

Dave... bring the green board down to the top of the base... actually butt the board right down on top of the base WITHOUT overlapping the edge.

Then you will fill the VOID left between the board and the base with a thinset mortar which helps to reduce wicking in the future.

If you bring green board in so it overlaps the base edge it will cause a bow in the bottom of the walls you will be installing soon.

Other choice is to fur out walls a 1/2" and then can overlap base, but you will still keep it at least a 1/4" off the base and fill with thinset mortar, etc...

I usually just butt down on top and fill joint... this also effectively LOCKS the base in place all around perimeter edges! Base will never move!

Good luck on the cutter... plumbing supply will have it or I'm mailing one to you on Monday afternoon... ;)

Talk later...

MARK

Mark, the base was made about 3/4" smaller than the actual space so I filled in between the base and the stud framing with the mortar. It should never move. The base has about a 3/8" lip all the way around. I thought it would have like an inch or so. That way the walls would set down on the lip then I could caulk the joint. I've never seen a shower where the walls stuck out further than the lip around the base. I need to find something like 1/4" thick to put on the walls before the marble walls. Either that or I could just put the marble walls against shims on the framing.
Any thoughts?
Dave

Put the 1/2" green board on the wall as I suggested earlier.. butting down on top of the 3/8" lip... then fill the void between base and cement board. That will pull walls beyond lip of base... then you can install cultured-marble wall without it bowing out.

PS..with cultured marble walls I think you are better off with a mold-resistant green board....but installed as above.

I edited my above post to reflect that as well.

I'm getting confused now. Here's a drawing of what I'm working with.

That shower pan should sit wall-to-wall. I think you should build-up that 3/8" gap between framing and shower pan. Also, green board may not be sufficient for marble wall tile installation. You should use backing board instead, or float it.

Milo is right about cement board if this was a marble stone wall... but this is a cultured-marble wall panel and manufacturer of these walls recommend green board because you will be using an adhesive to bond wall panel... not thinset.

I also agree with Milo in that you should fur those walls out the required amount so that base meets stud... the entire wall. Then you add the 1/2" wall-board which should leave you beyond the lip of the shower base... fill void between base and wall-board. Then install wall-panels as required using appropriate adhesive and add silicone or mildew-resistant caulking between base and cultured-marble panels.

Hope that made more sense.

MARK

Ooops... thanks for clearing this out for me, Mark. I was under impression that "cultured marble" is a culture marble wall tile. You are correct. Green board is just fine.

Only one point from my experience, if I may: I would not use Liquid Nails type adhesive. It is dark brown and believe it or not - you will see the bead of caulking through the wall panel after installation.

So I think I get it now. Fur the walls out to even with the pan, install greenboard which will then overhang the edge of the pan by 1/8", install cultured marble walls on greenboard but setting all the way down on the shower base. Is this correct? Also, Mark, you said to use silicone as adhesive for the wall panels right?

I used a white mortar because of the same reason. I didn't want to be able to see the mortar through the marble.

Yes.. silicone is best here! Milo is right again... Silicone won't bleed through walls, but set wall panel so it is 1/8" off the base (use shims temporarily). Then pull the shims when all is dry and apply the final silicone bead so it sets deep under the panel.

Your pic. Is correct!

Good luck.

BTW, I got the inside pipe cutter today so don't worry about sending me one,, ;)

I would have... Just so you know!

Keep 'em coming... :)

Mark

Crud, now I guess I'll have to move the shower valve out too.

Crud is right...

Good that YOU caught that now... although some manufacturers make extension kits for just this situation...

What manufacturer made your valve?

Ummmm, it's a Price Pfister shower valve. It's not too hard to move though. I need to re-center it anyway.

That and I have to figure out how to transition from the regular drywall area to where the shower walls will start.

If I understood you...

I would just fir out the rest of the wall(s) so that there is no transition... just need to rip some firring strips and tack in place until drywalled... then drywall/greenboard line up without transition and walls look smooth!

Let me know if I misunderstood...

Well, I already have drywall on the rest of the room. I guess I can pull it down and move it all out or at least slowly taper the firring strips up to the shower. I might see if the guy from the marble place has any different ideas. He has to come out and measure for the walls anyway.

I don't see why he couldn't cut a border that is say 2" wide and 3/4" deep... then you can butt your walls up to the border and transition should look very smooth!

Just an idea... ;)

Yes, that sounds like a good idea. I'll recommend that to him.