# Shower pan liner/drain question



## aaron_a (Dec 18, 2013)

I'm doing a bath remodel right now. I showed up after the lumber did his rough-in and noticed how he set the drain. He beveled the subfloor so he flange sits sub-flush with the subfloor. There is also no pre slope.

Should I pull the liner and put down some deck mud? And will havin the drain flange sitting low like that cause any problems?


----------



## MarkJames (Nov 25, 2012)

Who's doing the actual shower? Are they experienced (not just tile setting), i.e familiar with the various methods, how they work...and what not to do?

You're asking a pre-slope question (yes), but I'm wondering why. Not trying to be smart, but there's a lot left to the imagination in your post.


----------



## aaron_a (Dec 18, 2013)

Thanks for the reply. I will be doing the install. I have tiled a few bathrooms, but this will be my first shower pan.


----------



## MarkJames (Nov 25, 2012)

Even if it is your first pan, have you seen or helped others build them at all? I hope so. If not, it's not right to do this for a customer. You owe it to them (and yourself) to be sure you know how to do it right. Quick questions here aren't going to be enough.

Know anybody experienced that can help you? Or looked at any tile sites that walk you through building a pan, using deck mud, etc? The old phrase "you don't know what you don't know" may apply here. And it can be a costly headache later.


----------



## aaron_a (Dec 18, 2013)

I'm not one to jump into something new without at least doing some homework first. I've looked at several sites (john bridge, finehomebuilding, jlc). I have any understanding of how it works, how they are built, just no hands on time with doing them. In all the reading I have done, all the pans have the drain set on top of the subfloor, with a pre slope mud bed underneath the pvc liner.


I do have a buddy who is a pretty spectacular tile setter I could call.


----------



## MarkJames (Nov 25, 2012)

aaron_a said:


> I'm not one to jump into something new without at least doing some homework first. I've looked at several sites (john bridge, finehomebuilding, jlc). I have any understanding of how it works, how they are built, just no hands on time with doing them. In all the reading I have done, all the pans have the drain set on top of the subfloor, with a pre slope mud bed underneath the pvc liner.
> 
> 
> I do have a buddy who is a pretty spectacular tile setter I could call.


Drain needs support, even if the base is recessed. I would call that buddy...(and don't let him tell you that "you'll be fine without a pre-slope")!

How are you building the rest of it? Have you considered Schluter, Wedi or any of the other stuff out there? How about some pics?


----------



## aaron_a (Dec 18, 2013)

I was planning on: pre slope mortar bed over felt and wire lath, pvc liner, and mortar bed on top. Tile with thinset directly on top of that. It's an odd shape so I figured the mortar bed would be simplest. 

Tile buddy is gonna swing by tomorrow to take a look.


----------



## gbruzze1 (Dec 17, 2008)

A common mistake is not putting any pea gravel or even tile spacers around the drain so that the weep holes don't get clogged. You can do everything else right but skip that step and the whole system is shot.


----------



## aaron_a (Dec 18, 2013)

Well my buddy just stopped by. Maybe he's not as spectacular as I thought. He said I don't need the pre slope. Maybe people just don't do that around here...

I still plan on doing the pre-slope though. Wil having the drain inset into the floor cause a problem?


----------



## Nick R (May 20, 2012)

If I remember right, if the drain is recessed into the floor, it may make it difficult to screed the pre-slope correctly, having to feather it out to nothing, where as if you had the drain flange set correctly, you screed to the top of it leaving the thickness of the flange at the thinnest point of the pre-slope.


----------



## mikeswoods (Oct 11, 2008)

How to build a shower - Building a shower pan with pre-sloped mortar bed, liner and curb.

This will give you the basics---I never put tar paper or mesh into the preslope---

I've build a bunch like this---


----------



## MTN REMODEL LLC (Sep 3, 2010)

With a conventional vinyl liner, yes you want a preslope bed under the liner.....that is exactly why your drain has weep holes.

I suppose in theory you could leave just the liner with no slope without a leak per se..... but your shower stall would always be moist and get moldy. I have just heard that it will get nasty with time. I have never heard/seen of that assembly ever done without a preslope.

Yes..... I think your recessed drain will be a problem.... look at your drain and see where the vinyl liner is supposed to flange into the drain.
I usually build my preslope bed about an inch thick at the drain (gets thicker obviously at 1/8 to 1/4 per foot as it slopes up and outward.)

Sounds like your drain is so recessed that the liner would not neatly flange into the drain.

As to your top/tile bed, your drain grate will have alot of screw adjustment in it, and it will screw down right to your top/tile bed


----------



## MTN REMODEL LLC (Sep 3, 2010)

mikeswoods said:


> How to build a shower - Building a shower pan with pre-sloped mortar bed, liner and curb.
> 
> This will give you the basics---*I never put tar paper or mesh into the preslope---*
> I've build a bunch like this---


I'm with Mike..... I don't use mesh in my bed....... but I've seen it done... but I always put a nice 3/4 piece sub floor ply in to make sure that everything is solid. Some felt won't hurt... noy so much as an uncoupler but more so the ply does not suck cement moisture... which is alfull dry to begin with...... and pack the hell out of that dry pack bed.

Best


----------



## gbruzze1 (Dec 17, 2008)

I do it just as shown in the link. I don't build the pre slope up am inch at the drain though as mentioned above. I tell my plumbers to raise the drain about 1/2" above the plywood. Usually the drain has lugs on the underside that will rest on the plywood and keep the drain raised the 1/2". 

Does anyone build their curbs as shown, with wire lath? That's how I usually do it, but someone once told me that the lath will cut a hole in the liner. I don't know of a better way to do a traditional mud bed and curb (not talking about schluter systems). Any thoughts?


----------



## mikeswoods (Oct 11, 2008)

I've never worried about the mesh damaging the liner--or ever heard of that happening---that is some tough membrane---


----------



## aaron_a (Dec 18, 2013)

Thanks for the replies. Here is what it looks like. I looked up the part number of the drain, and it looks like it is made to be beveled into the floor like that. Is it for some type of shower system I'm not familiar with?


----------



## gbruzze1 (Dec 17, 2008)

No that's wrong. Just about every plumber by me does it the way that you've shown. When I tell them how I am doing it they all look at me like I'm crazy and say they've never done it like that. It's pretty crazy how rampant improper installations run. Anyway, you've been shown the right way to do it. Here is a pic of the installation instructions directly from oatey and another from Sioux chief. Notice each shows a pre-slope.


----------



## TNTRenovate (Aug 19, 2010)

It's installed wrong. It needs to sit on the subfloor.

I would install 15# felt as a slip sheet. It allows the subfloor to move independent of the pan. You can use mesh to stiffen that preslope, but with a proper mix, you don't need it.

Install your preslop pan using a preslop pitch kit. Makes your life so much easier. And this is why you need the drain on the subfloor. It sits 1/4" above the subfloor, which is the perfect height to pitch to.

Then install the liner making sure that it goes at least 8" up the wall passed the finished liner height. I always go 10"+. Also a good tip is to make sure your framing will except the dog ears in the corners. Being able to tuck the dog ear in the wall keeps the fold from bulging your tile substrate.

Install the mud bed using a perfect pitch kit. Then your tile substrate on the walls. Make sure that your walls are plumb, even and square if possible. Plumb and even are more important IMO. Shave any studs that crown out and fir out any that are not flush. I also recommend to backer behind the joints (even if they are on 16" centers). Bring your backer down to the finished pan.

Now you need to address your walls. Like it has been said, there are many products you can use to water proof the walls. I prefer a brush or roll on membrane like Aqua Defense or RedGaurd. Using fibafuse tape I first adhere the fiberglass tape to all seams. Bedding them in a coat and placing a coat on top. I also will fill all screw holes at this time with the a coat.

Now brush over entire surface giving your walls two coats and seams three.

I allow this to dry 24 hours and then skim coat all seams with modified thinset. This makes the surface nice and flat. By the time I finish the coat is dry enough to start laying tile.

You can lay the floor first, which is what I recommend, or after your walls are up.

I would also recommend using a urethane grout.

If you feel the need to caulk any corners or seams prior to water proofing do so with acrylic caulk.

Hope that helps, and I say all of that to also agree with Mark that you really should have someone that has done this before to help show you the ropes. It isn't fair to your customer to experiment on their home. At least do one for yourself and then move to your client's homes.


----------



## aaron_a (Dec 18, 2013)

TNT, by back do you mean putting blocking behind the seams? Sounds like a smart idea to me. I agree with you, in a perfect world, it would be ideal to have someone walk me through it. But, it seams like everyone around me thinks this is a perfectly acceptable install. My tile guy said doing a pre-slope was probably overkill, and hes the one who got me the damned job, so he should have some skin in it. My plumber said hes done this "hundreds of times in his years of plumbing, and this is the way reputable tile guys like it done".

Thinking back on it, I was on a job over the summer as a carpentry sub. I noticed none of the shower pans had pre-slopes either. I pointed it out to the gc, who said it was fine the way it was. I went back there last month to fix a couple things someone screwed up (guess who? it was the tile guy). And I noticed all the grout lines in the shower floor were looking pretty dark and saturated.

The plumber did say he will re do the drain if I need him to. So I am going to call him and get that taken care of.

I have two more people I can call to help me out. If that doesn't work I'm on my own. My first job in the trades was working for a roofer. We did a few rubber roofs, and I'm at least familiar with working with a membrane and dealing with water. It's my name on the line, and my clients money. I really want to make sure this gets done right.


----------



## mikeswoods (Oct 11, 2008)

The pre slope doesn't have to be perfect---a proper mix helps---makes packing the mud easier---

For the top bed---I simply scribe a line around the pan where I want the wall to meet the pan----and start packing----never tried the plastic gizmos mentioned earlier----couldn't see how they would help---it's just not that hard to sculpture a pan with the wall line and the drain set to work off of.

I always use a square drain cover---Cutting into a round one is much more difficult---


----------

