Yeah they don't actually tell you that you need a min of 3/4" to achieve the listed R value to take advantage of the radiated properties. You lose a couple digits if you just mount the foil side up against something.
Construction adhesive and wooden blocks for the attachment and spacers. You can see some of them up top. The adhesive is supposed to work up to 200* but even if it doesn't and it unsticks from the siding, it won't matter because the boards can't move once they're covered up anyway.
Definitely not a professional installation but as long as it works, I really don't care. I just need workable temperatures during the summer, more space, a lift and I'll be a happy man.