Travertine mosaic wet room height problem

[David Dudley]

Hi guys.

I have installed a AKW tuff tray former to my bathroom directly to joists with lots of extra noggins, etc. I also removed all the existing t+g and replaced with high quality 18mm marine ply (sbr primed under and sides) again with lots of noggins.

Originally my shower was to be enclosed with a small curb/step separating the tray from the floor - so the height difference wasn't an issue.

The floor is rock solid with no deflection on the floor or tray and is nice and flat and level.
As its so solid and level I have now decided that I would like to make the tray level access so I have a 4mm height to make up.

I originally decided to use Dural CI+ to make the floor level to the tray and then overlap with Dural WP to make a seamless waterproof transition between the former and ci mat.

We are using 48x48mm travertine mosaic for the shower area (which I want to extend beyond the former) and 600x400travertine for the main floor.

I am now concerned that as we want to use travertine mosaics that the ci is unsuitable for this.

As an alternative I thought about using the ci mat for the main part of the floor (big tiles), leaving a gap of about 200mm between the mat and the former. Filling the gap with slc - then overlaying the lot with WP and mosaic on top. The theory being that the mosaics would be supported with the SLC and the bigger tiles by the ci matt.

I looked at using 4mm cement board but worry this is too thin. 6mm cement board +2mm adhesive would be too high. Other option 6mm no more ply screwed and glued.

How important is the CI matt for the travertine on ply? Would it still be needed of I use no more ply?

My preference is the SLC idea, does anybody see any problems with this?


Thanks.
David.

 

[David Dudley]

View attachment wetroompic1.bmp View attachment wetroompic1.bmp

Hopefully this picture shows what I am trying to achieve. The AKW former is smaller than the total area to have the mosaics, so I was planning to raise this area with SLC (or maybe Tile Adhesive) to meet the level of the CI matting where the larger tiles are, and then the WP membrane over the top of it all to make a waterproof seal?

 

[micko]

Hi,
I’m just a keen diy bloke, why can’t you use you CI under the trav mosaics? I thought it was good down to a 20mm tile size.

 

[David Dudley]

According to the Dural Datasheet you shouldn't use tiles less than 50mmx50mm - maybe I'm being a tad pedantic asking about 48x48mm?

QUOTE

By reason of design DURABASE-CI++ mats are not suitable for laying under thin or large-format​

floor tiles (”slimline tiles”). There is a risk of them breaking. In addition, small-format tiles under​

50 x 50 mm must not be used either.


This raises another question - it mentions not to be used under thin or large-format floor time ("slimline tiles")
Does this mean that you can't use the matting with 600x400/12mm tiles or is it just referring to thin large format tiles?

 

[micko]

I would guess you should be OK, 12mm is not a thin tile and as for the 2mm too small I would go for it.
But again I’m not a pro. Give Dura a call.

 

[thompsonbrown]

in my opinion i would overboard the 18mm ply with 4mm ply to give you the same height as your wet room tray. Then use a tile safe membrane to cover the whole floor have a look at the tile safe membrane kit used with impey aquadec system.