Safety and security glass has come a long way since the days of wired glazing thanks to significant advances in glass-making technology. Today’s superior products can offer much more than simply protection.
From banks and shopping centres to offices and schools, modern safety and security glass allows specifiers and installers to create aesthetically pleasing buildings, while protecting the people inside.
Although safety and security glass are closely linked, there is a key distinction between the two. It’s crucial that developers and installers alike understand the difference between these products if they are to specify the correct glass.
Safety glass is designed to reduce the risk of accident by impact or fracture and protect occupants from resulting shards of glass. Because of this, it should be installed in areas within a building that could be impacted by the occupants, particularly doors, door side panels, windows and low-level glazing in general.
The two most common types of safety glass are toughened glass and laminated glass.
Toughened glass is manufactured by subjecting glass to a heating and cooling treatment whereby high compressive stresses are set up at the surfaces with balancing tensile stresses in the centre. The high compressive surface stresses give toughened safety glass its increased strength, resulting in panes typically four or five times stronger than ordinary glass. When it does break, it tends to fracture into small, relatively harmless fragments.
Laminated glass differs as it has a PolyVinylButyral (PVB) interlayer sandwiched between two panes of glass. If broken, the interlayer holds the fragments of glass in place. While it is technically no stronger than traditional glass, this interlayer makes it safer for people as it reduces the risk of occupants coming into contact with broken glass and injuring themselves on harmful shards.
While safety glass applies to glazing that reduces the risk of an accident by impact or fracture, security glass is designed to withstand various deliberate attacks. Laminated glass in particular offers considerable security benefits, and when correctly installed, its resistance to penetration can help to protect against bullets, explosions and manual attack. For high security areas, much thicker laminates with many more interlayers may be appropriate.
It’s important to remember that glass alone cannot protect a building and it can behave differently depending upon the framing system used. To achieve the level of protection required, it’s imperative to combine high performance glazing with high quality framing systems.
Although safety and security glass are designed with protection in mind, the presence of PVB in laminated glass also offers acoustic insulation. Furthermore, by combining various thicknesses of glass with acoustic PVB interlayers, increased levels of acoustic protection can be achieved, should a building be located near to a source of noise disturbance, such as a building site or a busy road.
Similarly, advances in coating technology means that today’s safety and security products incorporate a number of advanced performance benefits including, solar control, thermal insulation, self-cleaning and anti-condensation properties.
Specifying without compromise
With so many glazing solutions available on today’s market, fabricators no longer need compromise on any element of a specification. Modern technologies allow manufacturers to offer end-users the very latest performance, often in the same window, while meeting the strictest safety and security standards.