Ceramic Tile Advice Forums - John Bridge Ceramic Tile

Ceramic Tile Advice Forums - John Bridge Ceramic Tile (https://www.johnbridge.com/vbulletin/index.php)
-   Tile Forum/Advice Board (https://www.johnbridge.com/vbulletin/forumdisplay.php?f=1)
-   -   Updating shower (https://www.johnbridge.com/vbulletin/showthread.php?t=128378)

clegg 12-04-2018 09:52 AM

Bathroom tile over Vinyl
Hi all, I am planning to upgrade my master bath floor from builder grade sheet vinyl to 12x24 tile.

The house was built in 2005 (St Louis area) and has from what I can tell 3/4 OSB with 1/4 plywood and then the vinyl is adhered with a mastic.

I was trying to avoid the mess of removing the vinyl. Can I go over this with a cement backer and then the tile?

I was looking to use DensShield for the backer, any opinions on this?

I've done tile floors before, but on a concrete slab.

Thank you.

greenjp 12-04-2018 10:23 AM

Unfortunately the 1/4" ply and vinyl combo is a no no. I pulled out the same in my place prior to tiling. I got a breaker bar and was able to pry the whole thing up pretty easily. You'll probably have many little staples to deal with but they're not so bad.

You also need to figure out what the underlying joist structure is to determine if you need another layer of ply on top of the 3/4".

cx 12-04-2018 10:41 AM

Welcome, Ed. If you'll add that geographic location to your User Profile it'll remain permanently in view to assist in answering some types of questions. :)

What Jeff said about evaluating your joist structure first. You can use the Deflectometer in the dark blue bar above to get an initial go/no-go reading on that.

Putting a CBU over what you've got would not likely be acceptable to any CBU manufacturer, but I suppose you could do it if you want. That said, DensShield is not a CBU, but rather a fiber-reinforced gypsum board. You'd need to contact Georgia Pacific to get a specific answer to your installation plan, but I doubt they are going to like it.

My opinion; worth price charged.

clegg 12-04-2018 11:49 AM

Thanks for the info so far. This is on the second level, so difficult to determine the joists. The first floor looking from the basement is engineered beams (silent floor).

So if I tear out the vinyl, does the 1/4" ply have to come out also? The vinyl comes up easily.

greenjp 12-04-2018 01:00 PM

You may be able to determine the joist spacing by using a stud finder on the ceiling below the space, or by looking at the screws in the floor after you've ripped up that vinyl and 1/4" ply :) Educated guess as to the specific model of joist you've got by looking at exposed ones. They probably used the same ones throughout. Also figure out the unsupported span based on the lower floor's layout. Once you know that (say a 14" TJI 120 at 20" spacing or whatever) you can find the manufacturer's specs for deflection.

Lazarus 12-04-2018 01:01 PM

Yes. 1/4" has no place under a tile install...

clegg 12-04-2018 02:34 PM

OK. It's coming out.

clegg 12-08-2019 01:18 PM

Updating shower
Hi all.
I have been a member for about a year now and have decided to redo my shower stall. It is currently a builder grade shower (acrylic pan center drain 34x48 and cultured marble walls) with sliding doors.

I want to make the shower wider by roughly 4-5" as the existing curb is inset by that amount from the wall.

This is on a second floor master bath. The subfloor is osb 3/4".

My plan is to tear out the existing pan and walls and install the durock pre sloped shower system.

The closest sloped pan I can find for my application is a 48x48 pan. Now that my drain is already centered, can I just cut the pre sloped foam more from one of the sides to keep the drain hole "centered" with the pre slope? Will there be draining issues with one side a bit lower? The 48" long will remain, just the width needs to be about 39".

I was also wanting to do a walk in type curbless setup. I understand that the subfloor would need cut out.

Carbidetooth 12-08-2019 01:34 PM

If you cut, say, 5" off sides of pan, your perimeter will be uneven, which will mean your bottom course of tile will be unlevel in order to follow floor.

Zero entry shower necessitates waterproofing well into the room. I suspect you'd need to remove more than the subfloor to gain depth needed. That means structural changes. Without knowing actual structure, those changes are typically easier over crawl space as opposed to living.

Curbs don't have t be huge and that would simplify things a bunch in your case.

FWIW, I like more pitch in shower floor than any foam pan I've seen provides, but I'm fussy that way.

cx 12-08-2019 02:36 PM

Welcome back, Ed. :)

I've merged you with your previous thread on this bathroom project so folks can see what you're working on and what's been previously asked and answered. Be good to know what you finally did for your subfloor and tile installation.

Gotta agree with Peter. I would rarely favor those foam shower trays even when the fit the shower footprint and drain perfectly. A simple sloped mud floor is much more robust and allows for a perfectly level perimeter.

I see we know nothing about the structure under your subfloor, so I can't help with the design of a curbless shower installation. Your being on a second floor with living space below is gonna make necessary alterations difficult at lease and probably not possible for the cuts you'll need for the shower depression. There are pre-fabbed shower receptors on the market designed specifically for your application, but I have no experience with them and can't recall the brand of any right off the top of my head. Perhaps someone else will.

My opinion; worth price charged.

ss3964spd 12-08-2019 02:40 PM

What Peter said, Ed, though I'll disagree a bit with water proofing well into the room; really depends on the size of the shower and if you have a door or curtain.

All pre-made foam pans have a fixed perimeter thickness, mine was 1". As Peter said, if you cut any side of the pan off it won't be as thick there as it is on the 3 un-cut sides, so your tile will be lower on the cut side than it is on the other 3 sides. How much depends on the slope of the pan. Also, the pre-made pans demand a sub floor that is both flat and level because they may have the bare minimum of slope built in.

Doing a curbless shower will usually mean increasing the height of the entire finished floor. On a wood framed floor think of it this way; If you set a premade pan with a perimeter of 1" on the existing subfloor you would need to raise the rest of the floor almost 1 1/8" to be even with the top of the pan (1" for the pan, + approx. 1/8" mortar under the pan). And that's before floor tile and mortar, which will add probably 5/8" (typical 3/8" floor tile + approx. 1/4" mortar) so now you're somewhere around 1 3/4" from existing subfloor to the top of the tile - which doesn't include any water proofing if it's needed.

clegg 12-08-2019 03:00 PM

Thank you all so far.

The shower is 48"wide x 36" The curb is on the 48" and will have a pivoting glass door with a smaller fixed glass panel (Aston Belmore).

I guess I could just go with a lower curb height to eliminate the need to lower the pan area or raise the surrounding floor. I tiled the floor about a year ago. I should have used the thicker CBU.

I have reservations about a foam board as the base, but seems easier than troweling that concrete base and using a vinyl liner and then another base on top.

Can a single base be sloped and use the Schluter or Durock membrane over?

ss3964spd 12-08-2019 03:08 PM


Originally Posted by Ed
Can a single base be sloped and use the Schluter or Durock membrane over?

Yup. But the since "mud" base still needs to be at least 3/4" thick at the drain, with a 1/4" per foot slope, so you'd still be around 1 1/4" pretty thick around the perimeter if using a center drain with the almost 48X48 size you mentioned.

clegg 12-08-2019 03:21 PM

The floor will be 48x36. I would have to use a 48x48 and cut down to 36 wide if I used the Durock pan.

So if I did tar paper then a cement base of 36x48 sloped over the subfloor and membrane over, that will waterproof properly?

I decided against the curbless design.

ss3964spd 12-08-2019 03:28 PM

Yes, it would.

But now that you'll have a curb you will have to tie it into the water proofing as well.

Don't know if you are doing this job to meet any/all local building codes but if so you might want to check into what those codes are. My local code says that IF a curb is used then the top of the curb needs to be at least 2" higher than the top of the drain grate.

All times are GMT -6. The time now is 02:41 PM.

Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright 2018 John Bridge & Associates, LLC