Klober air-open underlay tops performance ratings

// the building envelope

The variable performance of vapour permeable underlays prompted the NHBC and BSI to decide that only air-open membranes may now be used without supporting high level ventilation. Klober Permo® air offers the UK’s highest level of breathability, a feature which is critical during a building’s drying out period. With a water vapour resistance confirmed by the BBA as 0.03 MNs/g, it is regularly specified for roofing upgrades of high profile and historic buildings, new builds and complex roof designs.  Permo air has also been tested for wind uplift resistance by the BRE.



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