This white paper aims to provide some clarity around the specification and installation of window and façade interface sealing membranes. It addresses the challenges faced in selecting the appropriate membrane for each façade interface application and emphasizes the importance of compliance with regulations and performance standards.
The paper discusses the two main types of membranes used in building façades: those used for creating water and airtight seals around windows and interfaces, and those used for providing a vapour-permeable protective layer behind cladding. It highlights the need for fire classification in all construction membranes and explains that traditional EPDM membranes are no longer compliant due to their combustibility.
The regulatory requirements, including Regulation 7 and Approved Document B, are outlined. These regulations establish minimum fire classifications for façade materials used on relevant buildings. The paper points out that any deviations from Regulation 7 and Approved Document B can only be implemented upon written dispensation from Local Authority Building Control.
Applicable testing standards for sealing membranes are discussed, with EN13984 governing performance requirements and EN1928 specifying water-tightness testing methods. The importance of considering both fire classification and performance standards in membrane selection is emphasized.
Installation methods and techniques are described, emphasizing the need for compatibility, primer application on porous surfaces, proper paste adhesive spread, and effective membrane bonding. Corner sealing and edge capping are highlighted as critical aspects for ensuring a watertight seal.
The concept of future-proofing is introduced, suggesting the consideration of compliant membranes that exceed current standards to minimize the need for costly retrofits as regulations become more stringent. Product availability is also mentioned as a challenge faced by contractors and the need for ensuring a robust supply chain is in place.
In conclusion, the paper emphasizes the responsibility of all stakeholders involved in specifying and installing membranes to focus on both performance and compliance requirements, to ensure that we all play our part in creating safer buildings.