Structural Adhesives road to A1 and A2 ratings

If you were to ask any professional in the construction industry their number one concern at the moment they would undoubtedly say combustibility of materials. After the tragic events of Grenfell tower the general public have (rightly so) been questioning the fire safety of buildings they live and work in. Pressure is building on manufacturers to supply materials that are lower risk in terms of fire safety. An announcement from the government calling a ban on combustible materials on buildings over 18 m has made the issue all the more urgent. As assistant chemist at Structural Adhesives Ltd this issue has lately been taking up a lot of space in my mind.

The guidelines to fire safety of materials are by no means straight forward. Words such as combustibility, flammability, fire-resistant and fire-retardant all have different meanings but are often used interchangeably by corporations making it difficult to determine what is required. My initial investigations into fire rating regulations unearthed a number of different classification systems (each with their own criteria) which left my head spinning, and I can’t be the only one.

Thankfully to ease some of the confusion the government have specifically mentioned one the of systems, the Euroclass system. It has been stated that only materials classified as A1 and A2 in this system will be permitted for use above 18 m. A1 and A2 ratings correspond to non-combustible materials and materials of limited combustibility respectively. But are these materials available to buy? The answer is yes, to an extent. For example, there are cladding and brick slip systems available that are A1/A2 rated but how are these designed to be fixed to the building? If the answer is an adhesive then is this adhesive also A1/A2 rated? Adhesives usually used for these applications contain large amounts of carbon and are by no means non-combustible.

A truly non-combustible adhesive designed for bonding cladding, now that’s something worth thinking about.