Vent 3® Classic is a breathable roof underlay that gives major benefits over traditional underlays. The Cromar breather felt is made from two high-tensile, spun-bonded polypropylene layers. This triple-layer, high performance, breathable membrane is thermally calendared to a micro-porous polypropylene film.
Layer one - waterproof surface
Layer two - breathable waterproof membrane
Layer three - protection from abrasion and damage, giving additional strength
This product has exactly the same specifications as the Vent 3 Light breathable membrane, but the Classic has a heavier GSM at 115 than this Light's 95 GSM.
Clean and easy to use
Lightweight and flexible
Waterproof membrane
Long-term durability and tensile/tear strength
BS 5534:2014 compliant
Application
Can be used in supported or unsupported roof systems, regardless of whether they are tile, slate or metal, and in warm and cold roof applications.
Equally effective whether draped unsupported over rafters or laid directly onto insulation.