Adhesive Advice For Fixing Insulation Boards

[jjoc]

Guys,

Just looking for some advice on fitting some insulation boards.
I have removed the asphalt so back to a concrete floor as asphalt was very loose and breaking up - came up easy.
Now looking to but 10mm ins boards down, once primed.......my question is:
For a concrete floor would you use a flexi addy or just a regular rapid set? can't find any spec from the manufacturer.
I will obviously be using flexi for going on top but wasn't sure about underneath.

Thanks

 

[White Room]

I'd use a flexi to stick the boards down for peace of mind....

 

[J Sid]

What make are the boards?

 

[jjoc]

The boards are made by Jaco.....they're a foam board not the cement ones.

 

[Qwerty]

Foam encapsulated cement faced board. I use S1 personally, the same as I am sticking the tiles down with