From Kingspan
Nilvent is a breathable membrane for use in unventilated pitched roofs and timber frame walls. PROPERTIES: Water vapour resistance 0.10 MN.s/g Liquid water penetration Classified as W1, when tested, unaged, in accordance with BS EN 1928: 2000 – Method A Nail tear strength 130 N in the longitudinal direction 145 N in the transverse direction Roll length 50 m Roll width 1.5 m Thickness 0.4 mm Area per roll 75 m2 Weight 0.13 kg/m2 Weight per roll 9.8 kg