Powerlon UltraPerm Lite Vapour Permeable Roofing Felt - 50m x 1.5m Properties Grade: 92gsm. UltraPerm lite: Breathable roof underlay for all warm & cold, ventilated & unventilated pitched roof designs. Ultraperm lite can also be used for walls as a breather & air barrier. Application Pitched roofing felt. Metal clad roofs. Breather wall protection. Description Developed as a universal breather membrane, Powerlon UltraPerm is a high performance underlay for all roof designs. It can be used on warm and cold, supported and un-supported, ventilated and un-ventilated roofs. It is a non-woven composite membrane with exceptional water vapour transmission, hydrophobic (water repellent) characteristics and good UV stabilisation. The membrane also has good air barrier characteristics designed to improve the air-tightness of the building. Powerlon UltraPerm is a top of the range third generation breather membrane for traditional cold roofs and modern warm roof installations. Powerlon UltraPerm is tough, tear resistant and durable with superior performance to traditional felts. Powerlon UltraPerm is BRE certified for warm and cold, supported and un-supported, ventilated and un-ventilated roof constructions and covers the UK and the Republic of Ireland. Features Universal breathable underlay for any roof design. BRE certified. High water vapour permeability. Exceptional water resistance. High nail tear strength. High tensile strength. Pre-printed marking lines. Illustrated installation instructions with each roll. Manufactured to ISO EN 9001 quality assurance with full batch traceability. Flame retardant.