Is Laminated Glass a Combustible Material?
Following the Grenfell disaster in 2017, many changes have been made to the fire safety regulations. One amendment to Approved Document B in particular has affected the balustrading on balconies when at height. The amendment banned the use of all combustible materials on the external face of buildings over 18m tall. To be compliant materials have to achieve a fire classification of A2-s1 or A1 classified, in accordance with BS EN 13501-1:2007 + A1:2009. So is laminated glass actually a combustible material?
A number of items were excluded from the ban, including window frames and window glass. However these exclusions didn’t extend as far as including laminated glass in balustrades. It is typically recognised across the industry that toughened and laminated glass is considerably safer in balustrades. The aim of a balustrade is to protect the edge from falls, and laminated glass ensures that there is still a barrier there, even in the unlikely event of a panel breaking. The PVB or SGP interlayer holds the broken pane together, until it is safe and convenient to replace the panel.
Toughened glass by itself meets the requirements for being A1 fire rated. It is only once it is laminated that the use of it in balustrades is not allowed. The ban on laminated glass at height is because in isolation, a PVB or SGP interlayer will burn. However fire is is only possible when oxygen is present, and once sandwiched between 2 panels of toughened glass this is not possible.
Therefore common sense and logic indicates that toughened & laminated glass will not be combustible, when looking at the whole product holistically. However safety regulations rule otherwise, so at the minute toughened & laminated should not be used in high-rise buildings. So the answer is laminated glass is not a combustible material, but is classed as one in the regulations.
