Products > Nilvent > nilvent > Overview nilvent Breathable membrane for unventilated pitched roofs and timber frame walls Kingspan nilvent Breathable Membrane Properties Download PDF Buy it Now Water vapour resistance 0.17 MN.s/g Liquid water penetration > 2 m Nail tear strength 210 N / 50 mm longitudinal 135 N / 50 mm transverse Roll length 50 m Roll width 1.5 m Thickness 0.5 mm Area per roll 75 m2 Weight 0.14 kg/m2 Weight per roll 12 kg