No More Ply, Or Insulation Boards?

[Flintstone]

how do chaps, been reading on here from time to time and thought I would sign up, so,ex good info on here.
I have a job coming up, 90sqm or large format porcelain.
The floor is concrete and is having underfloor heating mat throughout. The question is what to put down first, just concerned about the foam boards, apparently, the tech support for the foam boards said a 6mm screed of slc would be required over the wires to give it the strength. Sounds dodg to me. no more ply stuck down with flexi rapid gonna be a good option ?

 

[Andy Allen]

I would go with insulation boards, the slc over the heating mat is to protect it and help disperse the heat. ..

 

[Flintstone]

I'm just not convinced by the strength of the boards

 

[peteablard]

I'm just not convinced by the strength of the boards

Why not?

 

[Flintstone]

I've tiled over them previously on a concrete floor and it didn't feel rock solid under foot.

 

[Andy Allen]

There more than strong enough......I know they don't look like much but it's all about spreading the weight, ...

 

[peteablard]

Not sure why, as Andy said above I'd stick boards, SLC over the cables then tile.

 

[Flintstone]

Just stuck down with rapid set? Is there anything wrong with sticking no more ply down with rapid ?

 

[Andy Allen]

Think you will find most tilers on here tile over insulation boards with no issues at all...........
I thought no more ply had to be stuck with there own glue.

 

[Flintstone]

It looks like they have ordered the no more ply so will be going down that route!