Do I need To Tank walls before tiling my My Shower/bath?

[jamesc1979]

I am re-tiling my bathroom and I am unsure whether I need to tank around the bath and shower before tiling.

I live in a basement flat with concrete floors and masonry walls.

I have a bath with a shower at one end.

The shower will be fixed above the bath to a false wall made from Wbp ply.

The other two walls around the bath are masonry with a plaster skim.

I plan to use Ceramic tiles with cement based water proof adhesive and grout. I am going to use the powder type that comes in a bag. Can I just use this, or do I need to tank the walls first?

The original tiles that were removed didn't have a tanking system.

The bath is already fitted, so I am reluctant to stud the walls out with the waterproof backer board, but not sure if this is necessary anyway?

I have found a tanking system which is a BAL WP1 Tanking Coating, which is a paint on system.

http://www.tilefixdirect.com/product/BAWP1C.html

Is this necessary or can I just tile the walls?! [GALLERY=media, 51373][/GALLERY] [/img]

 

[tpt]

you'd be best to tank it, it just prevents expensive problems - and for the sake of 40-60quid its not worth avoiding.

dont use WBP ply on your false wall, use a backer board instead.