Wall prep for tiling?

[mmdowson]

As part of my bathroom conversion to a shower/wet room I am looking to tile all the walls.
The walls around the shower area I have reboarded with tile backeboard and will be taping all the joints prior to tiling. Will I need to apply a waterproof membrane to these walls awell?

Also how should I prepare the following wall surfaces for tiling?
1. painted/plastered block walls.
2. Painted/scimmed platerboard walls.

 

[DHTiling]

which make of backerboard is it.?

 

[mmdowson]

Hardibacker

 

[White Room]

What tiles are you fixing..

The paint needs removing at least.

 

[andy8758]

Hardibacker is strongly water resistant, but not waterproof. If you have already boarded, then you should coat the walls around the shower with a suitable waterproof compound - there are many good ones out there from manufacturers like BAL, Mapei, and Ardex. Also Homelux do a matting waterproofer. I have tried all these and had no problems with any - prefer Ardex if in a hurry.