Insulation board selection

[Tiling&bathrooms]

Hi all, some advice would be helpful here. I have a job coming up with natural stone. Part of the floor is being heated with a 12m2 mat. The substrate is a 20yr old concrete screed. My question is my insulation board choice. The mat will be a 200 pro warm mat. I believe that a 6mm board would be the best choice as I want to limit how much the level is raised. My usual suppliers are quoting around ###### a board (0.72m2) which are the cement skimmed foam boards however I am seeing several online retailers selling the foam only board which say that are suitable for my project at only #### a board (0.72m2). This obviously represents a good materials saving if they have the same properties as the higher priced ones.

Anyone used the blue or orange foam versions and will they do the job well if I fix them with a flex adhesive then fibre latex over the mat prior to laying the limestone?

Your thoughts are appreciated. Cheers



*****Edited by admin- no prices allowed in open forums please*****

 

[Ajax123]

how many square meters you doing

 

[One Day]

They're garbage and after faffing around trying to stick your mat and after compressing all over place, you'll wish you spent a few extra quid!

 

[Ajax123]

They're garbage and after faffing around trying to stick your mat and after compressing all over place, you'll wish you spent a few extra quid!

I agree but I was wondering how many square meters... if its 12m2 then the OP is querying maybe £90... not really worth quibbling about IMO. Spend the extra do it with proper gear and avoid having to revisit the site later when it fails....

 

[Tiling&bathrooms]

12m2 mat but area is 26m2 so instead of using so much latex I was going to board the whole area hoping for a similar cost anyway and additional thermal benefits versus just latex

 

[Uheat - Jake]

XPS Insulation would be fine for you're project and would give you better U-Values then a cement based backerboard. If it's a high quality XPS Insulation then you won't have the problem as Impish mentioned of them compressing. We've sold over a million of the 6mm XPS and haven't had one issue with them.

 

[Tiling&bathrooms]

What tech requirements please? Regarding adhesive primer etc?

 

[Uheat - Jake]

What tech requirements please? Regarding adhesive primer etc?

We recommend to prime the floor first, preferably a thermal primer. The boards then need to be stuck down with 2mm flexible tile adhesive.

 

[Tiling&bathrooms]

Super. Prime the boards before UFH mat and latex self levveller? Cheers

 

[Uheat - Jake]

Super. Prime the boards before UFH mat and latex self levveller? Cheers

Boards can be primed before mat and then 6-8mm slc over the top of the cables. Give me a call, I can sort you out a price for this project.