Advice needed on bathroom floor Advice and information on tiling and fixing tiles to a variety of surfaces

[Archiethere]

Hello, at the moment I have wooden floorboards down in my bathroom, my plan was to cove these with backer board before tiling, however I could do with some of the floorboards elsewhere. Due to various jobs involving electrics and plumbing some of my other floorboards are knackered and need replacing. I’d like to take the floorboards up and replace them with some WBP plywood. What’s the minimum thickness I can get away with? I’ve read that I should use 25mm, is this correct? I’m trying to avoid too much of a step up in height as you enter the bathroom. Any help would be greatly appreciated, thanks

[stoneyboy]

Hi Archie there,
If your joists are at 350mm centres 18mm ply will be ok. If they are at 450/500mm centres you will need the 25mm ply.
Regards S

[Archiethere]

Thanks, they are at 350mm. I just need to get hold of some ply now!