I've took up the old floorboards in the bathroom and once the plumbing is done intend to start putting it all back. All walls have been plastered and skimmed. The joists are no more than 400mm apart. I plan to:

1. Lay a 1400 (trimmed to 1300) x 900 x 22mm Marmox Showerstone tray in corner of bathroom directly on to joists.
2. Lay 18mm WBP plywood screwed on to joists supported by batons where required.
3. Lay 6mm Marmox board on top of WBP plywood.
4. Tape edges with Marmox water tape and apply liquid tanking to tray and walls in shower area

I have a couple of questions:

The floor will be 24mm (18mm ply + 6mm marmox) and the showerstone 22mm, will this 2mm difference be okay ?
I plan to screw the marmox down with the plastic washers to the ply, but should I also use an adhesive? if so any recommendations?
Any recommended products for tanking the tray and immediate shower walls/area before tiling?

Advice much appreciated!

Matt

You can get 4mm marmox boards


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So they do, seems only a few places do them and they're more money then the 6mm :-S

Have you tried PHG Wetrooms, link on the left of the page


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Originally Posted by Dave

Have you tried PHG Wetrooms, link on the left of the page


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Was going to get the showerstone and waste from PHG, looking on their website the lowest Marmox they do is 10mm so was going to source the 6mm from elsewhere. Maybe worth giving them a call to see if they do do the 4mm.

If I stick with the 6mm, can the difference be made up in adhesive when tiling the tray?

Yes they can get it, any worries etc , just give them a ring and say you are a tilers forums member


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Finding it hard to source the 4mm. I take it i'd be okay with the 2mm difference? especially with the tray being lower, as that's the way I want water to run

2mm shouldn't cause you any problems

How you getting on Matty? youre doing the same as me

I have 18mm ply and 4mm marmox boards and a showerstone too....

I'll let you know after this weekend Dave. I've changed the 18mm ply to 18mm chipboard. I plan to have the floor and tray down on Saturday. Where did you get your 4mm marmox from?

Why the change from ply to chip?

Got it from marmox direct, as they are only a few mins away in the car.

Hope it goes well mate... im nearly ready to start mine!

Chip is cheaper, and I thought if i'm putting marmox on top, then i'd be okay to use chip, plus its easier to handle 2.4 x 600 sheets. I'm also doing a fair bit of boxing in using 12.5 marmox, also plan to use this for the bath panels. What's your plan? what shower tray size you going for? You planning to screw the boards down or use adhesive, I think i'm going to use adhesive, and marmox silicon for the joins, and tape! :-D

I went for a showerstone 900x900 tray. Im going to lay direct to joists (floorboards all taken up) support under drain hole.

18mm ply around for whole room (small bathroom)

Im going to use adhesive on the marmox and also their silicon and tape too. Im not sure whether to use a tanking membrane aswell though.. or just paint on some liquid tanking. Im inclined to go liquid as marmox is pretty waterproof!

I have 12.5mm marmox for all the walls.. direct to studwork. Ill screw these (and seal joins with silicon and tape too)

I am using pumped waste system for the drainage though.. and a concealed shower / pump so still have to fit all that lot first!

Wish me luck!

sounds like were doing pretty identical projects! keep in touch mate with progress I will too