Tiling a bath side panel

[alantaylor]

I've tiled a bath panel with standard wall tiles and waterproof adhesive onto 20mm exterior ply. Problem is the ply has since warped badly (length-ways) - too much to ignore. What has caused the warp and how should I do it?
Alan

 

[gcol]

Was the ply screwed to the frame properly? Did you provide enough framing support in the middle of the sheet and screw to it?

 

[alantaylor]

I am trying to make a removable panel, so intended to screw it to the frame after tiling & finish with screw caps. I want to have access to pipework, isolating valves, etc. under the bath end.
Alan

 

[gcol]

That explains why you were using thick ply. Ok, you have a choice - you could try another ply panel but before you tile it give it a few coats of wood preservative (all over both side and edges) to minimise the effects of moisture. Or you could use something more stable - MDF is more resistant to warping than ply, but you really do need to make sure you seal it properly (again a few coats of preservative are needed).
I have a removable tiled bath panel, but I tiled over an existing MDF bath panel and that's been rock solid for years.
Good luck this time.

 

[alantaylor]

Thanks very much, will try MDF. I had already sealed the ply but on one side - perhaps contributing to the problem.

 

[Moz]

gcol is bang as normal correct .. would recommend /bal gear,(initial substrate was cr*p) for it ....

 

[grrinc]

Forget wood and us Wedi tile backer boards.

 

[crazycanuck]

last post is correct!
plywood and MDF will absorb moisture must use backer board (cement Board) do it right now and enjoy forever.

crasycanuck