Permavent APEX is a 3 layer breather membrane for use as a pitched roof underlay. Permanent APEX is both vapour and air permeable providing unique condensation control which eliminates the need for low or high level ventilation. Permavent APEX also provides a secondary barrier to water ingress.

APEX has been endorsed by NHBC for use as an unsupported roof underlay in cold pitched roofs without the need to provide any ventilation at either high or low level. Permavent APEX is fully compliant with BS5534 and the integrated tape allows APEX to be installed in all UK wind zones, as well as giving added watertightness on low pitch roofs.

Permavent Apex Air Permeable Underlay 50m x 1m

  • Size: 1m x 50m roll

    180 g/m2

    Weight: 9kg/roll

    Fitting Instructions

    Air and Vapour permeable membrane

    Integrated Tape (25% less membrane usage)

    Use without ventilation

    NHBC approved

    Conforms to BS5534

    LABC Certified

    3 layers membrane

    For use on any types of roofing/walling applications

    UV stable for 3 months