which scrim to use on MR Plasterboard / Hardibacker joints

[Steve_Bcs]

Hi, prepping room for tiling. 6mm hardibacker on floor and 12m in shower area. rest of room & ceiling is boarded with moisture resistant plasterboard,
I know to use alkaline resistant scrim on the floor & shower corners where the hardibacker joins but as I'm using cement based tile adhesive, what scrim do I use where the Hardibacker and MR boards meet the ceiling and for the walls MR board joints. Do I use alkaline resistent everywhere ( expensive) or only on the hardibacker boards.

 

[Flintstone]

Anywhere that’s going to get tile adhesive on it!
You could do with tanking the hardie in the wet area awell.

 

[Steve_Bcs]

So alkaline resistant everywhere then.

I though hardibacker didnt need tanking according to their litetature so i hadnt considered that. I am happy to tank though What tanking product would you recommend?

 

[Bill]

Hardie is bringing their own tanking system out soon........... that tells you something.

 

[Steve_Bcs]

So what tanking product would you suggest in the meantime?

 

[LM]

ARDEX WPC - Flexible Rapid Drying Waterproof Protection Coating - http://ardex.co.uk/product/ardex-wpc/