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‘Extreme’ wall membranes deliver class W1 performance for severely exposed sites

Protect Membranes, UK producer of construction and roofing membranes, has introduced two new waterproof breather membranes designed for use externally on timber frame, SIPs and CLT wall panels, achieving a Class W1 resistance to water penetration.

Launched in tandem with the STA Advice Note 18 published by the Structural Timber Association and NHBC, the products are designed for buildings sited in severely exposed locations which are typically high altitude, open to high winds and on westerly coastal sites in England, Ireland, Wales and Scotland.

Protect Thermo Extreme is a low emissivity, insulating breather membrane with microporous film and microperforation technology to ensure high watertightness and vapour permeability.  This protects the outer sheathing from moisture and allows vapour to pass into the external wall cavity.  Featuring a highly reflective surface, Protect Thermo Extreme helps deliver low overall U-values when the foil faces into an unventilated airspace, achieving an aged thermal resistance R-value of 0.77m2K/W, incorporating printed branding.

Protect TF200 Extreme is a high performance membrane used on the cold side of the insulated panel to minimise the risk of interstitial condensation, with microporous film technology to ensure high vapour permeability and exceed requirements recommended by TRADA and NHBC. It offers a temporary, first line of protection to the whole of the external wall.


John Mellor, Product Manager comments, We are delighted to introduce these two product additions to meet the need for a Class W1 external wall membrane in severely exposed areas, based on the new advice from the STA. With our market leading Protect TF200 Thermo and TF200 ranges continuing to be used widely throughout the UK where in the majority of cases Class W2 is acceptable as stated in STA Advice Note 18, it now means that we can offer a comprehensive range of membrane options to our customers throughout the UK and Ireland.”

Both membranes are CE marked, available ex-stock in 3m widths and 100m lengths and produced in the UK.

Click here to view more detail on Protect Thermo Extreme or click here to view more detail on Protect TF200 Extreme.

For more details, visit, email or call 0161 905 5700, quoting Extreme.

Related products

Protect Thermo Extreme insulating breather membrane

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Protect TF200 Extreme breather membrane

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Glidevale Protect is a division of Building Product Design Ltd.

Other subsidiaries include ventilation systems specialist Passivent and Kingfisher Louvres, manufacturer of aluminium louvres systems.

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