ARBO ARBOShield Pro External Perimeter Class A Membrane (EPAM®) is a self-adhesive perimeter sealing membrane designed to deliver a fully airtight, watertight, and fire-resistant seal around façade openings. It is intended for professional use on projects where fire performance, compliance, and installation efficiency are critical.
EPAM® achieves a Class A2-s1, d0 reaction to fire to EN 13501, making it suitable for buildings over 18 metres in height (11 metres in Scotland) and for other high-risk environments where Approved Document B compliance is essential. The membrane exceeds current Building Regulations, helping to future-proof façades against evolving fire safety requirements.
The membrane combines a robust carrier with an industry-leading self-adhesive backing, allowing it to form a secure bond to substrates even in extreme conditions. Adhesion is effective at temperatures as low as -40°C, enabling year-round installation and reducing programme delays during cold weather. This makes EPAM® particularly valuable on large-scale or time-sensitive developments.
EPAM® is primarily used to seal the interface between window and door frames and surrounding façade elements, including concrete frames, steel frames, and SFS systems. It can also be used at parapet walls, balcony thresholds, and other perimeter details where continuity of the fire and weather barrier is required. The membrane delivers Class W1 water resistance and very low vapour resistance (sd ≈ 0.06), supporting effective moisture management while preventing water ingress.
Correct installation is essential. Substrates must be clean, dry, and free from contamination. EPAM® is supplied in roll widths of 150mm, 250mm, and 330mm as standard, with bespoke widths up to 1 metre available for complex detailing. The self-adhesive backing removes the need for wet-applied adhesives, reducing site waste and improving consistency of application.
When integrated with compatible ARBOShield membranes, sealing tapes, and fire-resistant mastics, EPAM® forms part of a fully coordinated façade sealing system. Used correctly, it delivers long-term airtightness, weather resistance, and fire safety at some of the most critical junctions in the building envelope.
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