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!

 

[hmtiling]

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

i wouldn't use nmp on a solid floor. The 6mm ones have a tendency to curl up when fixed with addy and not screwed. The insulation boards are definitely the way to go. Fixed down with rapid and slc on top.

 

[On one]

The think the only reason for concern for using insulation boards on such a large area would be if you used really thin boards and there was a risk of the boards being compressed too much by people trampling over them prior to laying the SLC.
If you can control/prevent who is walking over them there shouldn't be a problem.

 

[Tile Shop]

On a solid base, Marmox Multiboard can handle 40 tonnes per m2. Does King Kong visit often? It has been designed with this very purpose in mind, so I doubt very much its going to fail. The SLC will also help evenly spread the weight and heat distribution.

Also, using nomoreply will allow heat to go down into the subfloor aswell as up.... It will therefore run less efficiently and your running costs will be higher.

 

[Flintstone]

Apparently the tech support for whichever thermal board company said the thin 6mm board isn't strong enough for the job!

 

[Lee@emctiles]

confused, are we talking foam boards (ie uncoated) ?

I would go with 10mm DeltaBoards, a thermal insullation board (marmox/Wedi type) over No More Ply.

 

[Tile Shop]

We do the thermogroup econoboard and never had any complaints or failures. Way cheaper than some of the coated versions like the marmox above. but laid with a solid bed and 5-6mm of SLC, once tiled will be more than tough enough,

My preference will always be coated boards though. Board wise for UFH I'd always go for insulation over cement based boards.

 

[Tile Shop]

confused, are we talking foam boards (ie uncoated) ?

Think that would be my fault.... misinterpreted the original post.

 

[ChiversTiling]

Can't fail with insulation boards + SLC + Adhesive + Tiles = job done

 

[Flintstone]

Not sure if they were supposed to be coated or un coated. It's having no more ply. I'm confident in that stuff. I don't think running costs are a concern to this customer!

 

[Flintstone]

Next time the situation arises, I will try the coated foam boards.

 

[Ian]

It seems that no more ply has good insulating properties, I never knew that. Ever day's a school day on the forum!

 

[culrossblue]

Nomoreply now do insulation boards in various thicknesses. That's the way to go

 

[Flintstone]

Turns out they have warm up thermo boards after all!

 

[hmtiling]

Problem solved. I was a wary about using them the first time but they are definitely what you want for that job

 

[Flintstone]

Any need to prime up the boards on either side?

 

[hmtiling]

I'd just prime the floor and the top of boards when fixed. The ufh will stick much better to primed boards

 

[One Day]

and don't spot-fix!

 

[Flintstone]

Got a good load down today, I would never spot fix any flooring!