Raising my shower tray

[pjo123]

Hi all.

Can I use 18mm exterior ply to raise a stone resin tray that will be set/levelled in sand/cement/PVA or does it have to me marine ply please?

Cant seem to find marine in under 8x4 sheets and it's VERY expensive.

thanks

 

[pjo123]

oops

Just read the tips sticky and it's covered in there. Yes I can use WBP ply instead of marine

Typical, centre of waste hole in tray is 140mm in from the edge, which is right across the middle of one of the joists, if it wasn't for that, I wouldn't need to raise it at all.