Recommended floor replacement to sit under bath

[wanleg]

Hi,

I've just taken out a leaking shower tray and plan to replace this with a shower bath. Prior to the shower tray being fitted a joiner installed some green coloured chip board onto floor joists...the previous tray before this one had also leaked so the original floor boards had to be replaced, it was this green coloured chip board that he used.

I now plan to install a shower bath in place of the shower tray, this chipboard seems to move a little under weight. My plan is to replace this board with something very strong and probably waterproof, anyone have any suggestions what to use ?...last thing I want under a new shower bath is movement from the floor.

Thanks in advance.

 

[masona]

Exterior plywood (WPB)

Waterproof glue are used in exterior plywood

Put in extra noggins between floor joists where the plywood butt joint

 

[wanleg]

Great thanks....I always got the impression that plywood was pretty thin but I see Wickes do this upto 18mm thick.