Class A W1 Breather Membrane
The Class A W1 Breather Membrane is a product of the ARBOSHIELD Pro® category. It is a high-performance vapour-permeable wall membrane with a low emissivity reflective surface and Class A2-s1,d0 reaction to fire – suitable for all light steel frame and SFS type walling applications.
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Class A W1 Breather Membrane – Fire-Rated Wall Membrane
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Unique properties of Class A W1 Breather Membrane
Resists the spread of fire across the cavity of the façade and can be installed onto almost any substrate.
Class A2-s1,d0 reaction to fire
Class W1 resistance to water penetration
5,000 hours tested resistance to UV exposure (equivalent to 9 months continuous)*
Suitable for modular off-site construction
Compatible with almost any substrate – sheathing boards, window frames, concrete, steel and blockwork
Airtightness: 0.093 m³/(h × m² at 50 Pa)
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Main Applications
Class A W1 is Suitable for a wide range of building types where fire performance and vapour permeability are both required.
High-Rise Residential
Meets fire performance requirements for residential buildings over 18 metres (11 metres in Scotland).
Schools, Hospitals & Care Homes
Class A2-s1,d0 fire classification makes it suitable for schools, hospitals and other high-risk occupied buildings.
Modular Off-Site Construction
Compatible with modular build programmes and off-site construction methods.
SFS & Light Steel Frame Walling
Designed for use with light steel frame and structural framing systems (SFS) in both new-build and refurbishment.
Technical Specifications & Downloads
| Description/Standard | Performance | |
|---|---|---|
| Reaction to Fire (EN 13501) | A2-s1,d0 | |
| Resistance to Water Penetration (EN 13859-1) | Class W1 | |
| Tensile Strength MD (EN 13859-1) | 3200 N/50mm BS EN 12311-1 | |
| Tensile Strength CD (EN 13859-1) | 3000 N/50mm BS EN 12311-1 | |
| Flexibility at Low Temperature (EN 13859-1) | -40 °C | |
| Water Vapour Transmission (ISO 12572) | 0.08sd | |
| Resistance to Nail Tearing MD (EN 13859-1) | 580N BS EN 12310-1 | |
| Resistance to Nail Tearing CD (EN 13859-1) | 450N BS EN 12310-1 | |
| UV Resistance | 5,000 hours passed (9 months continuous) | |
| Airtightness (EN 12114) | 0.093 m³/(h × m² at 50 Pa) |
Associated Products
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Class A Air & Vapour Control Layer - ARBOSHIELD Pro®
ARBOSHIELD Pro® Class A Air & Vapour Control Layer is a high performance air and vapour control layer featuring a low-emissivity reflective surface designed to combine Class A2-s1,d0 fire classification with high tensile strength, enhanced thermal performance and air tightness.
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Frequently Asked Questions
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Find your contacts
Regardless of whether you are an architect and planner, property developer, industry specialist, distributor, applicator or specifier – if you have any questions about our products, services or specific construction projects, please feel free to contact the CARLISLE® contact person in your area with your technical questions. Our experts will be happy to advise you.
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