gemininv

I am installing a boiler and an infloor heating system stapled to the subfloor from the basement of my house. My licensed plumber and I have have a simple question about the install. It is common in this part of Colorado to install a foil paper over the tubing to reflect the heat to the subfloor above. I have found rolls the the right width paper that come in two options. One is a double foil-faced bubble wrap material and the other is just double-faced foil paper. The bubble wrap is about 3/8 inch thick and has some limited r-value more than the double-faced paper. My first question is which material is preferable for this application . My second question is how to fasten the material. Do you staple through it or hold it up with the pieces of spring steel commonly used to hold up unfaced insulation? Could someone out their give me some of their expertise/ Thanks so much