Bathroom Ply Subfloor and Tiles

[Guido101]

Hello all,
Installing a new bathroom on a timber suspended floor, whilst attempting to get the final floor level as low as possible, and very confused about what I can tile on to!
I had imagined I could replace the existing floorboards with 18mm Ply straight onto the joists, and tile directly on to this, but it seems this is not suitable and some suggest having a 10mm back board fixed to the Ply subfloor to provide some movement for the tiles.
If using the backerboard, can I just use OSB instead of Ply and save the money? Is OSB suitable for a bathroom floor?
Any thoughts/advice on this would be very much appreciated!

G

 

[Deleted member 292770]

no

 

[Deleted member 292770]

.

 

[Guido101]

Hi God, thanks for the fast response - Ill go with your suggestion!

 

[Deleted member 292770]

.

 

[BarnabyT]

I always use a decoupling membrane direct onto floorboards, then tile straight onto it. Never had a problem and done a fair few.

 

[Guido101]

Thanks for that Barnaby - Will have a look into them, seen them used on Skillbuilder videos alot. Could you do that straight on to OSB do you think?

 

[BarnabyT]

OSB swells at the edges if it gets wet. If u replaced the floorboards with osb u might have to beef up the subfloor with noggins. U would also have to make sure the floor to wall junction was tanked if its in a wet area. OSB and chipboard aren't really appropriate for tiling even with a decoupled. Never really seen the need for expensive backer boards tho.

 

[Deleted member 292770]

.