thanks JohnD.
what is this rigid foam? is it same as Knauff space board ? do you have links to this product?
is fibre quilt same as glasswool, i.e space combi roll (http://www.diy.com/diy/jsp/bq/nav/nav.jsp?action=detail&fh_secondid=10186453)?
sorry, this is my first time doing a loft...