Andy Vooght looks at the use of fire rated glazing for passive fire protection in residential buildings. Glass has been used for fire resistance in buildings since the introduction of wired glasses in the late 1920s. Knowledge and materials have evolved significantly over the years and the specific requirements for providing passive fire protection, together with natural light, to the myriad of new and existing building types means that offering a piece of safety glass held in with a timber bead will no longer suffice. This often misunderstood area of passive fire protection plays an important part in the safety of buildings, but has developed out of the fenestration industry, where the expertise lies in other areas, such as energy performance, security, and ventilation. Whilst there are several systems on the market, much of the construction industry has made little effort to understand the specifics of fire rated glazing systems, perceiving them to be much the same as ‘traditional’ windows. Consequently, there has been little control over the supply and installation of these products historically, and as a result, there will undoubtedly be undiscovered issues hidden in plain sight, which can lead to problems identifying glazing systems in need of remediation. Compliant glazing The use of glazing within Approved Document B (ADB) is potentially complex to understand, but in simple terms tables B3 and B4 define the level of fire resistance required in specific locations within differing building types. Unless the scheme designer is adopting an alternative approach, it would follow that glazed elements would need to satisfy these requirements. Table B5 then further identifies allowable locations for the use of uninsulated glazed elements on escape routes. As the culture and legislation around the safety of buildings evolves, there will be many responsible persons keen to ensure they have things up to date and correct. In practical terms, this will include making sure that fire risk assessments are routinely undertaken and that the information pertaining to building safety is held as we work towards the Golden Thread. Based on the requirements of ADB it should be possible to understand the application – be it for compartmentation, protecting a means of escape, or protecting a boundary – and the level of protection required in a given situation. For new buildings, where the focus is on design and specification, the expectation is that there should be a reasonable level of understanding to deliver a building that is compliant. However, given the generally poor knowledge surrounding these products, it may be difficult for a fire risk assessor to determine if what is in place will meet this. ADB offers a Guide to Best Practice in the Specification and Use of Fire-resistant Glazed Systems, published by the Glass and Glazing Federation, as a source for further information. Whilst not fully comprehensive and long overdue for an update, it provides a good place to start. Identification of fire rated glazing There are very few specialist companies on the market for these products, but it is worth bearing in mind that the levels of understanding and competence within these organisations are greater than those of general glazing companies. These experts are often approached to help inspectors and fire risk assessors understand what glazing products they are being asked to look at. Whilst it is not always possible to identify the system used, there a number of basic factors that help understand what is in place. Firstly, is the glass marked? On the most basic level, fire resisting glass should be marked with the name of the manufacturer and the name of the product. Ideally, it would also contain the product standard the glass meets and the impact safety rating. If the glass is clear and carries no mark, then it should be assumed that this glass will provide no fire resistance. As these are glazing systems rather than just glass, to understand if the installed product is fit for purpose, it is necessary to also identify the framing system and wall construction. This begins with examining how the glass is fixed. Typically this would be into a timber, steel, or aluminium framing, which is then fixed into the structure. It is also vitally important to understand if there is appropriate test evidence for the size and configuration used at the level of protection required. It is also necessary to identify and understand the substrate into which the frames are being fixed to determine if the frames are correctly specified and fixed. Typically there will be limitations due to testing rigid or flexible constructions. It is also important to establish that an appropriate perimeter condition has been used. Evidence should exist for product classification against EN 13501-2, or ideally the scope would be covered by third-party certification (e.g. Certifire). We must remain mindful that much evidence for such systems would have been provided on the basis of technical assessments. The Passive Fire Protection Forum (PFPF) released its updated Guide to Undertaking Technical Assessments of Fire Performance of Construction Products Based on Fire Test Evidence in 2021 and the basis for opinion has evolved. As a consequence many previously allowable options are no longer permissible due to lack of primary test evidence. Finally, an expert will want to see evidence of how the installer of the system can evidence competence. As these installations differ greatly from traditional glazing installations, specialist knowledge is required to ensure that elements are fixed and finished in the appropriate manner. Simply having done this for a long time will not suffice and third-party certification exists for installers – e.g. FIRAS, which audits an installation company’s knowledge and capability on site, as well as the record keeping of installations. For current installations, requirements under Regulation 38 exist for the installer to provide the fire safety information to the responsible person. If such records do not exist, there will be doubt that the intended protection is fit for purpose. Understanding the requirements Where the requirement exists to introduce or replace such products, how should