Use GreenStuf Roll Form to avoid thermal bridging by double layering over the top of the ceiling joists. GreenStuf® Roll Form is an insulation blanket suitable for thermal and acoustic insulation of residential buildings. It can be used as a roof blanket, in ceilings, internal and external walls and in mid-floor cavities. GreenStuf® Roll Form is also idea for insulating the ceiling of existing homes. Installed as a blanket it can be simply rolled out over the top of the ceiling joists to create a warmer, drier home in winter and a cooler home in summer. GreenStuf® Roll Form is available in a range of BRANZ appraised performance options.