Hi all. I have had to take over completing a wet room after the original tiler became unavailable. Only the floor and shower tray are to be tiled as the walls are wetwall. Customer wants the floor and tray tanked and up the walls about 200mm. He has got hardibacker to overlay the floor but i'm not sure about tanking over all of that (about 4 sq mtrs in total). I know hardibacker is waterproof so think I only need to tank all joints and corners where it meets the walls. Also hardibacker is the best surface to tile to. If the customer still says he wants the floor to be fully tanked will it be better to just put down ply and tank over it completely. thanks.

it's a misconception, hardie is water resistant, not waterproof. Water will pass through it without it degrading that's all

Hardie is water resistant, will not break down when wet but can still get soaked, so I would tank...

Whats wetwall ???

Snap Doug

Thanks guys...should have realised it would let water past..just like powder addy. So would you guys put in hardibacker and tank it or just put down ply which is cheaper. I take it that hardibacker is easy to tank...just like plasterboard.
Wetwall is those big shiny laminated sheets of MDF...just stuck to the walls with silicon type adhesive. Not what I would recommend for a wet room...but as I said I have been lumbered with the tiling of the floor.

MDF disguised as shiny sheets, not my idea of fun.

If the customer wants Hardie........Give him Hardie

From the Wetwall website

Specification

Wetwall panels are constructed of Medite Exterior Grade MDF, covered on the face with high pressure laminate and balancing laminate to the back of the panel. Our waterproof gluelines are D4 rated. Wetwall panels come with a 10 year guarantee **