12 x Cromar Vent 3 Pro Breathable Membrane is appropriate whether draped unsupported over rafters or laid directly over insulation.
Providing a permanent quality breather underlay, which will last the life of the roof construction.
The membrane will allow the water vapor to escape from the roof structure. Also protect against wind-driven rain, snow, and dust.
When tested in accordance with BS5534 2014 Annex A , Vent 3 Pro felt is suitable to be in the applications below and zones attached.
The membrane’s high-vapour permeability, waterproof nature, and excellent tensile/tear strength make Vent 3 Pro an ideal product for use in warm and cold roof applications.