Fixing "Kingspan" type to the walls?

[Nos]

Now the house in more or less finished Iam looking at the garage/workshop, was wondering if I could just "Glue" this type direct to the walls, its a new house and because Iam in France they have used Terracotta blocks, so good thermal properties, but a nightmare to fasten anything to. As it is only for the cars and a workshop could I just line it all in ridged insulation? then just paint it white? what "Glue" do I need? I was thinking of just spotting a bit of expanding foam in eight of ten little bits and pushing the panel up against it the panels are interlocking so they all should help each other stay put thanks for your help.