Should anything be laid underneath marble floor tiles?

Should anything be laid underneath marble floor tiles?

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Discussion

wax lyrical

Original Poster:

934 posts

249 months

Yesterday (11:00)
quotequote all
...in a bathroom.

We're about to get a small en-suite redone and not sure what needs to be on the floor before laying the marble floor tiles?

Planning to use a rapid-set, cementous adhesive.

Chat GPT says:

Subfloor Preparation: The surface must be rigid and even to prevent cracking. Typically, a cement backer board (such as Aquapanel) is glued and screwed onto the subfloor using a rapid-set flexible tile adhesive for added stability and moisture protection [2].

Moisture Barrier: A waterproof membrane or underlayment is recommended to prevent water infiltration, which can cause staining or damage to the marble [6].

iphonedyou

9,609 posts

165 months

Yesterday (12:51)
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We used Ditra mat.

Danns

342 posts

67 months

Yesterday (13:01)
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+1 for ditra
The Marble supplier I used specified it

I also used 22mm no more ply T&G - checked with their technical team. Response was, although you shouldn’t have to use Ditra, they would recommend to be on safe side.

1.5 years on - no cracks / movement / noises etc. although it’s not a definitive proof - it’s better than omitting and having the other half go on at you for thinking you k ew better if something failed

wax lyrical

Original Poster:

934 posts

249 months

Yesterday (13:52)
quotequote all
Thanks Guys! smile

wax lyrical

Original Poster:

934 posts

249 months

Yesterday (14:05)
quotequote all
What about underneath porcelain tiles on the shower wall?

Can tiles be bonded straight to the wall, or should there be something underneath?

Crumpet

4,070 posts

188 months

Yesterday (14:46)
quotequote all
I did our en-suite in marble and four years on it’s still in good shape.

- Replaced floor boards with 18mm ply and braced all the joists; this made it totally rock solid.
- Wedi tile board (12mm) fixed to ply with combed-out tile adhesive and screws and all joints / fixings sealed.
- Electric UFH laid and levelled over with a flexible latex levelling compound (Arditex NA).
- Slow set white flexible adhesive (why make your life hard with rapid set!), buttering the backs and onto a combed bed. I think they’re 10mm tiles onto 20mm half round combs. I like the Rocatex stuff and haven’t had a single tile in the house move.
- Grout. Can’t remember which one but I bought the most expensive and it’s been great with no discolouration.

Did exactly the same up the walls with the Wedi board and sealant and it’s been perfect so far. I opted not to use Ditra mat because it was only a 3m x 1.8m bathroom and figured it wouldn’t be needed.

I actually made an inspection hatch in the ceiling below (it’s just a utility room) and it’s all looking perfect in the void so would absolutely do any further bathrooms exactly the same way (I’ve done two like this with no bother).

To me the biggest question is how to tie the shower tray into the wall. I just opted for tiling down to the tray and a big bead of silicone but I think next time I’d try one of the systems where it’s taped to the tray behind the tiles as well.

Vanden Saab

14,821 posts

82 months

Yesterday (18:05)
quotequote all
Crumpet said:
I did our en-suite in marble and four years on it’s still in good shape.

- Replaced floor boards with 18mm ply and braced all the joists; this made it totally rock solid.
- Wedi tile board (12mm) fixed to ply with combed-out tile adhesive and screws and all joints / fixings sealed.
- Electric UFH laid and levelled over with a flexible latex levelling compound (Arditex NA).
- Slow set white flexible adhesive (why make your life hard with rapid set!), buttering the backs and onto a combed bed. I think they’re 10mm tiles onto 20mm half round combs. I like the Rocatex stuff and haven’t had a single tile in the house move.
- Grout. Can’t remember which one but I bought the most expensive and it’s been great with no discolouration.

Did exactly the same up the walls with the Wedi board and sealant and it’s been perfect so far. I opted not to use Ditra mat because it was only a 3m x 1.8m bathroom and figured it wouldn’t be needed.

I actually made an inspection hatch in the ceiling below (it’s just a utility room) and it’s all looking perfect in the void so would absolutely do any further bathrooms exactly the same way (I’ve done two like this with no bother).

To me the biggest question is how to tie the shower tray into the wall. I just opted for tiling down to the tray and a big bead of silicone but I think next time I’d try one of the systems where it’s taped to the tray behind the tiles as well.
All spot on, Exactly how i do it. We silicone the tray to the wall, leave it for 24 hours then tile and silicone the tiles to the tray before grouting.