From Ryno
Ryno Breather Vents are designed to release vapour pressure from flat roof structure. They prevent membrane blistering by releasing moisture that may have been retained and trapped during construction. Key Features: Watertight seal created by dressing roofing membrane over the circular flange of the vent Breather vents available in EPDM for felt or asphalt applications, PVC for PVC membranes Allow water vapour to escape from the structure, avoiding blistering of the membrane