Flooring Tile - marble in shower

Stone contractor is putting marble in my new shower. He said he does not need the durock/cement board he'll be using mud doing the work old school Italian style he is also building the shower floor I have the liner in. Just wanted to know if this will work I don't want to have to tear my walls down in 10 yrs. If I need the cement board can I put it over the greenboard? I've seen his work and checked out his references and business there has been no complaints and he's been around for 30 yrs. He did superb work on my granite counter tops.

Lmax - your contractors plan is a good one.

THAT procedure (mud) is centuries old and much better than any of the cement boards.

Relax, sounds as if you are in good hands.:)

Thanks, I feel better, but I did cut out the green board about 8 inches from the floor all the way around so the plumber could set the liner. should I put the green board back or can I just put the durock there I have 2 sheets available.

Put the greenboard back and return the CBU.
Use the twenty bucks to take your significant other out for pie and coffee.:)

Thanks for the advice, hope to get the bathroom completed before he gets back from his TDY.

I'm no expert, but i don't think you want to puncture the liner.

Your tile guy should be answering questions like this.

He did I needed another opinion.

LMAX

When reinstalling the greenboard, you do not want to puncture the liner any lower than 2" to 3" above the height of the curb. If this is going to be an issue, you could cut the greenboard higher and reattach a larger piece so you don't have to nail through the liner.

"Good Catch" there JPicasso, when I read she had removed 8" for plumber access I must have stopped reading before I got to the word "liner' cause I missed that entirely.

Lmax, Johnny is correct. You will have to remove a bigger portion of the greenboard so that you have something to attach to the studs without piercing the pan liner with fasteners.:)

Sorry I didn't catch that, my bad.:)

Anybody care to find out if there is a pre-slope under that liner.:thinker:

What Tileman is asking, is the liner laying flat on the floor or is there a pitched mud slope under it so water that gets to the liner is directed to the drain. If the liner is flat, call the plumber back. The liner needs to be pitched 1/4" per foot towards the drain, and never flat on the floor. If he argues, share this with him:

Uniform Plumbing Code related to shower pan construction.

"412. 8 When the construction of on-site built-up shower receptors is
Permitted by the Administrative Authority, one of the following means shall
Be employed:
(1) Shower receptors built directly on the ground:
Shower receptors built directly on the ground shall be watertight and shall
Be constructed from approved type dense, non-absorbent and non-corrosive
Materials. Each such receptor shall be adequately reinforced, shall be
Provided with an approved flanged floor drain designed to make a watertight
Joint in the floor, and shall have smooth, impervious, and durable surfaces.
(2) Shower receptors built above ground:
When shower receptors are built above ground the sub-floor and rough side of
Walls to a height of not less than three (3) inches (76 mm) above the top of
The finished dam or threshold shall be first lined with sheet plastic*,
Lead* or copper* or shall be lined with other durable and watertight
Materials.
All lining materials shall be pitched one-quarter (1/4) inch per foot
(20. 9 mm/m) to weep holes in the subdrain of a smooth and solidly formed
Sub-base. All such lining materials shall extend upward on the rough jambs
Of the shower opening to a point no less
Than three (3) inches (76 mm) above the top of the finished dam or threshold
And shall extend outward over the top of the rough threshold and be turned
Over and fastened on the outside face of both the rough threshold and the
Jambs.
Non-metallic shower sub-pans or linings may be built-up on the job site
Of not less than three (3) layers of standard grade fifteen (15) pound (6.8
Kg) asphalt impregnated roofing felt. The bottom layer shall be fitted to
The formed sub-base and each succeeding layer thoroughly hot mopped to that
Below. All corners shall be carefully fitted and shall be made strong and
Watertight by folding or lapping, and each corner shall be reinforced with
Suitable webbing hot-mopped in place. All folds, laps, and reinforcing
Webbing shall extend at least four (4) inches (102 mm) in all directions
From the corner and all webbing shall be of approved type and mesh,
Producing a tensile strength of not less than fifty (50) psi (344. 5 kPa) in
Either direction. Non-metallic shower sub-pans or linings may also consist
Of multi-layers of other approved equivalent materials suitably reinforced
And carefully fitted in place on the job site as elsewhere required in this
Section.

Tilebri

Just curious. Do plumbers in your area know this and do this? Every job I do the plumber never puts in the preslope - I do. If its the plumbers reponsibility it never seems to happen. Best I can get them to do is put the clamping drain in at the right height so that I can put in the preslope. If you don't tell the plumber in advance they assume no preslope and the drain is set at subfloor height with no room for mud.

I don't know one plumber who installs mud beds, let alone ask if one is needed for this, my neighbor is a plumber now for 40 years, every lead pan was on a flat floor, untill he did a few for me, but of course I had to get there first for the pre-slope.;)

Attach the green board only at the top edge, minimal puncture. leave bottom, mud should push and keep bottom of greenboard in place.;)