Advice required regarding floor make up

[Olly123]

I'm refurbing my bathroom after a leak. I've ripped up the old tiles and the 6mm ply they were sat on and the floor boards underneath are in a bad state. They are 20mm t&g and I was wondering if I can replace them with 18mm t&g ply boards. The wife has decided that she wants UFH so I'm trying to keep the make up thickness to a minimum. After putting down the 18mm t&g ply I was then going to fit 6mm insulated boards, then UFH mat, SLC and then tile on top. My joist centers are 400mm, does this sound ok ?.

 

[Dave]

It’ll be cheaper to use T&G chipboard (22mm) and then the boards.

 

[Olly123]

It’ll be cheaper to use T&G chipboard (22mm) and then the boards

It’ll be cheaper to use T&G chipboard (22mm) and then the boards.

Dave, I'm trying to keep the floor make up as small as possible, 22mm is 4mm thicker. I would go with 15 mm ply if I could find any 😟

 

[Dave]

Dave, I'm trying to keep the floor make up as small as possible, 22mm is 4mm thicker. I would go with 15 mm ply if I could find any 😟

Too thin imho. Unless you nog it to death including all edges. You don’t want any bounce.

 

[Demuss]

Have you completed the bathroom floor?
I'm doing something similar except not replacing the bathroom floor. After insulation boards, UFH mat, SLC and tiles is going to be about 29mm thick.
What did you use at the doorway to transition into the next room?
Thanks
Anthony

 

[Ajax123]

Get rid of the insulation boards and insulate between the joists. That saves you 6mm

 

[Demuss]

Get rid of the insulation boards and insulate between the joists. That saves you 6mm

I'm tiling over t&g floorboards so aswell as insulating they are providing some sort of support so dont really want to not use them.

 

[CJ]

Insulate between joists as mentioned. 18mm ply, then 6mm hardibacke.
self level to encapsulate cable.......then tile.

Transition threshold bar 👍

 

[Ajax123]

I'm tiling over t&g floorboards so aswell as insulating they are providing some sort of support so dont really want to not use them.

If youre relying on a 6mm insulation board for support I'd suggest stop and get someone in that knows what they're doing...

 

[Etherglide]

Does anyone, and does the standard allow, tiling directly on top of the cable, encapsulating the heating cable in the adhesive? This is a test question.,I have a customer who knows his stuff. However, he's lacking somewhat in actual knowledge.