What is best for bathroom sub-floor?

[vrytir]

Hi guys,

I want to ask you what to use for sub-floor. Should I use marine plywood, exterior hardwood plywood (should I prime it?), MDF or chipboard?
What is the best in your opinion? Should I prime it, if so what to use?

Thanks

 

[Mike]

yes that's fine provided you can afford the extra height. the ufh will raise the height by a further 5mm or so too and ensure you cover the cables/matting with slc (self levelling) prior to tiling

 

[vrytir]

I will go for 18mm WBP plywood and 6mm tile mate backerboard as this is recommend for floors (12mm is not recommended as I previously wanted to use)

yes that's fine provided you can afford the extra height. the ufh will raise the height by a further 5mm or so too and ensure you cover the cables/matting with slc (self levelling) prior to tiling

I thought that I just lay underheating cables than use flexible adhesive to cover it and use this "cover" to tille straight on this.

When screwing backerboard to ply, do I screw in to the studs or is it O.K. just in to the plywood?

 

[White Room]

Screw just into the ply but make sure the ply is well fixed, I use Turbo screws from screwfix at 25mm for the backer board...

 

[Mike]

I will go for 18mm WBP plywood and 6mm tile mate backerboard as this is recommend for floors (12mm is not recommended as I previously wanted to use)

I thought that I just lay underheating cables than use flexible adhesive to cover it and use this "cover" to tille straight on this.

When screwing backerboard to ply, do I screw in to the studs or is it O.K. just in to the plywood?

if you use slc over the cables this will ensure the cables are fully covered and prevent any hotspots in the cable,it will also help prevent you damaging the cable whilst laying the tiles and it will give you a nice flat surface to tile onto.