Toughened glass is a popular material for many homeowners, architects, and specifiers, used in many contemporary commercial or residential buildings and installations. But what is toughened glass, why is it so extensively used, and what are its benefits? This article will give you more understanding of all these questions as well as some of the most common uses for toughened glass and its safety credentials which can be so critical to its versatility.
What is toughened glass?
Toughened glass, sometimes referred to as tempered glass, is a high-strength, lightweight safety glass that’s five times stronger than standard or laminated glass. Its strength is down to how it’s manufactured, known as the tempering process. Heated up to intense temperatures of around 650ºC, the glass is rapidly cooled, giving it an incredibly strong and durable outer layer.
When installed, toughened glass can stand firm and resist high pressures, shock, and heavy impact – it can even withstand extreme heat temperatures of up to 250ºC. But should it suffer breakage, toughened glass will shatter. However, its dense structure means it will break into hundreds of tiny pieces which have blunt edges rather than dagger-like shards that can be dangerous.
How is toughened glass made?
All toughened glass starts out as ‘float glass’ which is another name for standard, normal single-pane glass. Before it goes through its tempering process, the glass is cut to size – any attempt to cut it after tempering would cause it to shatter.
The tempering process starts by carrying the sheet glass on rollers through a furnace which uses even, radiant heat to heat the surface of the glass to around 650ºC. Once the temperature is reached, the surfaces are rapidly cooled by a short blast of cool air on both sides for anywhere up to 10 seconds while the inner area of the glass remains hot.
Due to the difference in temperature between the surface and inner, the glass takes on different properties that create compressive surface stresses and tensile inner stresses. These stresses give the glass increased breakage resistance and allow it to clump into small pieces rather than sharp shards if it breaks.
Toughened glass or laminated glass: which is better?
While toughened and laminated glass share similar properties, they’re actually very different in terms of the manufacturing process and their individual properties.
Toughened glass is commonly used in installations where strength and high resistance to heat are needed. These qualities see this type of glass used in areas with a lot of usage, such as car windows, shower doors, or even kitchen work surfaces making it a highly safe option. However, toughened glass doesn’t have any UV protection or noise reduction qualities.
Laminated glass goes through a very different manufacturing process. Two or more panes of glass have a plastic film sheet made from either EVA (ethylene-vinyl acetate) or PVB (polyvinyl butyral) in between. This is a true safety glass as the film layer prevents shattering on impact, holding it together to prevent falling glass shards. A popular and useful choice for areas with high footfall, like glass stairs or floors.
So which is better? Both types of glass can be used in different installations and have plenty of excellent features between them. Which one you choose will depend on which meets the relevant building regulations for your requirements.
The advantages of toughened glass
What is toughened glass really good at? When used in the right installation, toughened glass is a natural choice if there are any public safety concerns or if it’s to be used over a wider or taller area, such as internal walls or shop fronts.
Its tempered status gives a high safety level if it ever breaks as it fractures into small, blunt fragments. But it will take a lot for it to break as it’s created to have remarkable strength. In fact, it can stand up to extreme surface weights of up to 10,000lbs per sq inch and has temperature resistance up to around 250ºC (480ºF).
Common uses for toughened glass
As we’ve mentioned, toughened glass is useful in different commercial and residential installation types. But it’s an especially common and popular material for premium architectural use. A frameless glass wall of toughened glass is used in different installation types to give a high-quality, high-performance, and contemporary finish.
While certain criteria or mandatory requirements often need toughened glass to be used in certain installations, especially surrounding critical locations such as low-level windows and door panels, for safety and security, the lightweight and temperature resistance of toughened glass makes toughened glass ideal for a wide range of common installations, including:
- Office building and shop facades
- Glass doors
- Handrails and balustrades
- Contemporary building lifts
- Glass roofs and skylights
If toughened glass is used in installations, it must meet safety glass standards and building regulations. In such cases, the glass must have the official British Standards kitemark and the relevant code, which is BS EN 12150 for toughened glass.
Is toughened glass breakable?
In a word, yes – it is. But while toughened glass is five times stronger than ordinary annealed glass, making it a far safer choice, it can still be broken if there’s enough impact force to do so. Though it can withstand surface compression of up to 10,000lbs per sq inch, therefore covering many eventualities, it isn’t indestructible.
The most significant factor in toughened glass, besides its ability to withstand such extreme impacts, is that should it ever break, it doesn’t pose the threat of injury that standard glass does. When broken, toughened glass breaks into small chunks that don’t have sharp edges, rather than sharp, potentially lethal shards like standard glass.
Toughened glass from GlasSpace
This guide gives you a sound understanding of toughened glass and how it works. While safety and security are its most significant benefits, toughened glass is often used as a modern material, providing a contemporary finish wherever it’s required.
As designers and manufacturers of specialist frameless glass walls and facades, the GlasSpace team has the structural knowledge and experience to give you an expert consultation and provide you with specific installation details need for your installation. Contact us today for more information and your no-obligation, free quote.