Corotop Smart Breathable Membrane

Corotop Smart Breathable Membrane


A Three-layer Highly Permeable Roof Underlayment

The membrane’s high resistance to mechanical damages enables safe work at a height regardless of weather conditions. Corotop Smart 120G is a vapour permeable, tear resistant breather membrane.

Corotop Breathable Membranes form the water impermeable layer under the roof coverings in a pitched roof system. They can be used on open rafter (unsupported) or fully supported pitched roofs. The function of the underlay is to isolate the building from water ingress that may penetrate the roof coverings such as wind driven rain. In addition, the low vapour resistance of the underlays can, when correctly incorporated into a designed roofing system, assist with the satisfactory management of water vapour within the roof system.

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    What the experts have to say

    CERTIFICATE NO. 11/0367
    This Certificate relates to Corotop Breathable Membranes for use on tiled or slated pitched roofs. Corotop Breathable Membranes are manufactured by thermally laminating a water vapour permeable film between two layers of non-woven polypropylene. This Certificate certifies compliance with the requirements of the Building Regulations 1997 to 2014.
    • Minimize heat loss

    • Three-layer product resistant to influence of weather conditions and ageing processes

    • Regulate two-way vapour permeability

    • Protects thermal-insulation against damping

    Mass per unit area:
    120 g/m2
    Resistance to water penetration:
    Class W1
    Maximum tensile strength:

    Longitudinal: 300 N/50mm

    Transverse: 200 N/50mm


    Longitudinal: 60%

    Transverse: 100%

    Resistance to tearing:

    Longitudinal: 100 N

    Transverse: 200 N

    Flexibility at low temperature:
    Full Information:
    Check out the full datasheet available in the Downloads section!

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