Cultured Marble Shower

[TerryLee]

Just found your post & couldn't find anything particular to my project.
Our custom home was built 1995-96. Our upstairs marble w/ frameless shower door hinge failed to auto close after only about 5 years. Each use we would pull it closed many time it would creep back open slightly. This caused an un-noticed leak across the curb on one end where it disappeared into the carpeted floor. (yes carpeted bathroom floors) DEF not our choice.
This consequently rotted the plywood subfloor.

We had to remove all three marble walls and the marble pan and we have repaired the subfloor.
What we found under the pan was the Oatley membrane, with plops of some kind of Bed Mud /Sand mix sporadically spaced. (no pre-slope) There was a small amount of water as well.

The sub floor drain flange is not flush but sits on top and is 1/2" above one corner of a wall and 1/4" above the other corner of same wall.

The marble "floor" underneath is bowed upwards about 1/2". The drain is in the middle, there is a upward gap of I/2" when straight edged from on edge of slab to the other but it always seemed to drain okay.

1) What is to be done? What are the correct steps to put all this back together?

FYI We are preparing our house to be put on market, and I want to do it right for the next owner. This particular color is not avail and I am no prepared to repalce the marble.

[jonchicagoland]

Hi Terry,

I'm not entirely following what you're saying - you've removed all the marble, but there's still a marble floor somehow?

A few photos might save you an explanation and would help us visualize what you're working with
jon

[cx]

Welcome, Red.

Me, too.

[TerryLee]

Sorry for my delay, was out of town w/ family gathering.

For simplicity i will start over with shorter history with a few questions.

We have removed the marble shower walls and pan and have repaired the rotted subfloor underneath.

Presently shower stall subfloor is plywood only, drain is in the middle.

Am I correct to assume if the weight of the marble pan and walls sat directly on top of the new Oatey membrane would probably create holes in it?

[TerryLee]

Here is a pic of repaired subfloor for my shower as it is now.

[TerryLee]

As you see removing the marble walls the adhesive tore the paper of the green board.

The green board is structurally sound and dry. What do I need to do because of the torn paper

Is the 6.5" space at the bottom of the green board proper?

[TerryLee]

I am not sure if you can see but on the underside of the marble floor slab the center is raised about 1/2".

Across the top it is straight.

Should this be a concern?

[cx]

Originally Posted by Red

What we found under the pan was the Oatley membrane, with plops of some kind of Bed Mud /Sand mix sporadically spaced. (no pre-slope) There was a small amount of water as well.

Help me a bit here.

1. The Oatey (I'm guessing) membrane was on top of the "plops," or under the plops?

Originally Posted by Red

Is the 6.5" space at the bottom of the green board proper?

2. Was the membrane folded up into this gap, perhaps?

3. The membrane continued over the curb?

Any photos of the installation of the shower or of the shower being torn out that might give us some clues about the construction?

Originally Posted by Red

Should this be a concern?

4.Does the top of this composite floor slope uniformly toward the drain?

Either the plywood subflooring was incorrectly oriented in the original construction, or your patch is incorrectly oriented.

4. What is the thickness of the plywood? Did you install blocking under all the new joints?

[Davy]

So, originally there was a Oatey membrane (liner) on the floor?

Is this a curbless shower?

None of the marble needs to go in until you get the shower waterproofed. Are you planning to go back with a pan liner again?

[TerryLee]

shower had a 4.5" curb (3 2x4's) marble was attached directly to it

I will be building a new one.

Yes I will be installing a new Oatey membrane

Oatey was under the plops

Oatey was just touching the bottom edge of green board

It was on the inside of curb up to the top edge but not over

[TerryLee]

JUST TO MAKE SURE...

YOU ASKED
4."Does the top of this composite floor slope uniformly toward the drain?"

Are referring to the marble slab?

The plywood is 1" & yes absolutely added blocking on every joint, glued, and screwed it down. It is solid.

I appreciate this forum & everyone's help.

[cx]

The manufactured marble, yes. Is the top of it also bowed up, or does the top slope to the drain hole?

Given that the waterproof liner was laid flat on the subfloor, and only went up the inside of the drain, I'm not convinced that your rotted floor problem was caused only by water escaping out the shower door.

The way most of those composite/manufactured marble showers were put together, I can envision a number of places where the water could have leaked out. And you don't want to spend a lot of time and money just duplicating the problem. But yours did last longer than most in my experience.

If you plan to put a proper receptor under the new shower, you really want to do it correctly, the same as you would were you building a tile shower. Your manufactured marble is just the decorative coating that protects the waterproofed shower, the same way tile does.

The Oatey (or other brand) of waterproofing membrane should be properly sloped to your clamping drain and should extend up the walls to a height of 3 inches above the top of your curb, and it should extend up the inside of the curb and over the top. There should be no cuts or penetrations of any kind below a level of 2 inches above the curb.

You'd build that receptor as though it were for a tiled shower, then install your "marble" over that.

You agree with that?

My opinion; worth price charged.

[TerryLee]

Good Day!

About the rotted subfloor. First of all they built this house with carpet in the bathroom. Water leaked past the hinge end of the curb for years down into the carpet un-noticed until an approx. 8" hole in the subfloor rotted away.

Sorry about the pics being sideways, I don't know why they uploaded that way.
If you will look at the attached pic the hole was where the caulk tube is standing. The stained and softened wood extended outward from there.

Upon pulling up the marble and Oatey it looked as though water had wicked through the subfloor weakening and staining it. Just to be sure I cut out the subfloor well past any staining and replaced it.

[cx]

I think I had grasped where your rotted floor was, Red, I was just questioning how the water got there. Yes, running out the shower door could certainly do that, but leaking out through an improperly cut or installed waterproof liner could as well. Again, do you have any photos of that shower receptor during the tear-out that might give us a clue about the waterproofing?

And again I'm curious whether it's the original subflooring or your patch that's incorrectly oriented. Both should have the strength axis perpendicular to the joists, but they don't. And it might be helpful if you'd add a geographic location to your User Profile so we had an idea where you're located. I'm curious where an actual (or even nominal) 1" plywood is available.

My opinion; worth price charged.

[TerryLee]

MY BAD...

The plywood is 3/4" (actual). My location is Memphis Tennessee.

Sorry no pics with old Oatey installed. I just discovered two small pieces still nailed to the wall studs where the top edge are 8" off the floor.

With the curb being 4-1/2" plus 3/4 marble this placed the Oatey 2 3/4" above
the top of marble curb.

The top of the marble slab is basically flat. This explains why it took a while to totally dry out after a shower. But it would dry out.