My loft conversion has 70mm celotex fzr4000 insulation over my rafters unfortunatly as it is we appear to have only 40mm of space available for insulation. The BC doesnt appear to be to bothered unless its in the region of 100mm by the minimium height (stairs). I would like to try and achieve the minimium though in case of future problems.
Does anyone know of a high performance insulation that would give the same spec or over for this 40mm space.
