hi all again. a friend of mine has asked me if i could help him with his bathroom floor.

last time i asked on here i ended up with a really nice floor for my daughter everybody.

here for some more advise now if i may.

there is a full new floor that is chipboard laid on new joists but as the room was not intended for a bathroom when it was done the chipboard is not the water resistant green one. the joists span 10` and are 8"/2" at 13" apart. fully supported by noggins so there is very little room for movement by flexing. the chipboard is 22mm thick.

as this will be just the 2nd floor i have done i would like to get the pro advise again on doing it to the best of my ability.

do i need to do anything to the chipboard as prep work? should i tank it?

do i do the same as i did on the new floorboards with Hardibacker sheets, flexible rapid set adhesive & screwed down before tiling?

any advise appreciated again thanks.

Originally Posted by Pac

hi all again. a friend of mine has asked me if i could help him with his bathroom floor.

last time i asked on here i ended up with a really nice floor for my daughter everybody.

here for some more advise now if i may.

there is a full new floor that is chipboard laid on new joists but as the room was not intended for a bathroom when it was done the chipboard is not the water resistant green one. the joists span 10` and are 8"/2" at 13" apart. fully supported by noggins so there is very little room for movement by flexing. the chipboard is 22mm thick.

as this will be just the 2nd floor i have done i would like to get the pro advise again on doing it to the best of my ability.

do i need to do anything to the chipboard as prep work? should i tank it?

do i do the same as i did on the new floorboards with Hardibacker sheets, flexible rapid set adhesive & screwed down before tiling?

any advise appreciated again thanks.

Do the same as you did before mate

hi chipboard in bathroom not good best to replace with w/p ply 18mm min if you go the chipboard rout overlay with 6mm cement sheet screwed down then waterproof with membrane ps make sure there is no deflection in floor

thanks chaps.

changing the floor is not an option i have so it will be as above.

appreciate the input.

Originally Posted by jay

hi chipboard in bathroom not good best to replace with w/p ply 18mm min if you go the chipboard rout overlay with 6mm cement sheet screwed down then waterproof with membrane ps make sure there is no deflection in floor

Ditto

As long as the floor is stable and not used as a wetroom then overboarding with hardibacker will be fine..it will give a more stable surface for the adhesive to stick to and hold.

But it does need to be deflection free.

hello pac chipboard is not the way 2 go on bathroom floor You better off getting at least Half inch ply wood for the floor and screw it well down and seal it with a waterproof membrane hope all goes well for you.

thanks for the replies but it is quite surprising how Chinese whispers work. i clearly stated that changing the floor was not an option. i did also say it was already down and not originally meant for the bathroom.

as above, thanks for the help and i will proceed as stated.

hardiebacker route Pac