Installing Tile Backer Boards on Walls Outside in British Weather - Tile Advice

[gavinmrt]

Hi Everyone thanks for having me on the this forum ill try not to break any rules.

I am diyer these days but have 15+ years (in my past life) in the plastering and drylining trades.
I have had to carry out extensive works in my garden this summer to install drainage to carry water away from a steep slope. A lot of spoil and concrete has been removed and retaining walls have been built and tonnes and tonnes of clean stone placed back. On top of the clean stone i have used paving pedestals with 20mm porcelain. I used the pedestals to achieve some height and have the future ability to raise floor (if needed to access the drainage system underneath).
All good so far but now have to prepare the walls for a dedicated Tiler to come in and tile the retaining walls with porcelain wall tiles. I plan on mechanically fixing Tile backer boards to the retaining walls.

My questions:

• What brand and specification of boards should I be purchasing to withstand the weather in the welsh valleys?
• Can i start fixing the boards now knowing that the weather will close in any minute and the laying of the Tiles could well have to be put off until spring time next year?
• Will the boards be adversely affected by the winter weather when exposed?
• Can the tile backer boards touch or rest upon the floor when fitted? or should there be a gap between floor and wall to stop water touching the bottom of the boards? ( i was toying with the idea of using composite batten to rest the boards on to act as a barrier between wall and floor but this spoils the look a bit)

Any help or even discussion would be appreciated as I am not sure which way to go.

Many Thanks Gavin

 

[Andrew Owens]

Knauf Aquapanel cement board outdoor.

 

[SHIMADECOR-CARLOS]

You should pick tiles with zero water absorption, In cold weather, if the tile has a high water absorption rate, the moisture will condense in the tile body, and the tile will crack. Tile with zero water absorption rate is not afraid of freezing because it does not absorb water itself.