MR board shower tanking

[Julian 'Farmer' Bonsall]

Just to split out from the thread origin.

Using 12.5mm MR board in a shower with a liquid tanking membrane. Or use a cement board such as Hardi and tank? Thoughts ?

What are the differences between a cement board from hardibacker and say aqua panel ?

Between the cement board and a shower tray (type with legs) can a tanking tape be used as a joint between tray top and board then covered in tanking solution? Would it be sensible to use a sealant around the tray sides against the cement board as well ? And finally bring the tiles down to say 2mm above the shower tray and then seal with a good Silicon ?

 

[Paul Smith]

Commonly now XPS waterproof backer boards are being used in wet areas.

 

[Julian 'Farmer' Bonsall]

Paul. Thanks I had read a little about this but honestly hadn't considered.
So you mean something like XPS-Tile Backer Panel | Multi-Panels - Green and Fireproof Construction - http://www.multi-panels.com/xps-tile-backer-panel/ or Marmox?

 

[Paul Smith]

Yes, Wedi, Jacko, Marmox etc. Now use it rather than PB and liquid tanking or HB. Lots of info here on all of them.

 

[Julian 'Farmer' Bonsall]

Hi Paul very helpful.

So with say Wedi one still needs to tape all the joints (which can be coated/held on with tile addy?).
If used in a wet room is a tanking solution still useful due to the number of joints, floor and all? I get the boards are vapour proof. (I've only ever used that material for a wet room tray so no experience of walls and floors so to speak).

 

[GoneGuy]

I think with the wedi boards the joints gmhave to be taped with their specific tape and glue?
Also stud centres have to be closer to prevent any flex in the boards.