Much of the glass that’s used for residential and commercial applications is tempered safety glass. In short, tempered glass is heat-treated, making it about 4x stronger than regular, annealed glass. By design, when broken, tempered glass disintegrates into small pieces and is much less likely to do harm.
When shattered, tempered glass windows can help protect a building’s occupants and equipment from the hazards of large shards of fragmented glass debris.
Below, we discuss what makes tempered glass different from standard glass and its key benefits and potential downfalls.
What is Tempered Glass?
Manufactured through a process of extreme heating and rapid cooling, tempered glass is much harder than standard glass. Regular, annealed glass undergoes a thermal tempering process that increases its strength and changes its composition to shatters differently.
The glass is heated in a furnace to over 1,000 degrees Fahrenheit and then quickly cooled using high-pressure air blasts. This cools the outer layers of the glass much more quickly than the internal layers, so when the inside cools, it pulls away from the outer layers. As a result, the inside remains in a state of tension, while the outside goes into a state of compression. These competing forces are what make tempered glass so much stronger than annealed glass.
Due to the tempering process, when this type of glass is broken, it breaks into small, rounded chunks instead of sharp, jagged shards. Regular, untreated glass is known to shatter into sharp pieces called spall, which are a significant cause of injury in the cases of extreme weather or attacks like bomb blasts. Tempered glass is often referred to as “safety glass” for its ability to prevent spall and keep building occupants safe.
What is Tempered Glass Used for?
Also known as “safety glass”, tempered glass is often used in car windows, shower doors, glass tables, and other installations where increased safety standards are necessary. While the manufacturing process does make tempered glass more resistant to force, it is not shatterproof glass or unbreakable in any way. For this reason, it shouldn’t be used to prevent intruders, but it will stand up to more force than regular glass.
The tempering process also makes tempered glass more resistant to damage from higher temperatures. That’s why you may see tempered glass used in situations where high temperatures are likely to cause glass to break like in fireplace doors or kitchen appliances.
Disadvantages of Tempered Glass
One of the main advantages of tempered glass, its ability to shatter into tiny pebbles, can also be seen as a disadvantage. Since the glass is designed to shatter entirely upon impact, it can pose a security risk. Motivated intruders may find it easier to gain entry because a single force can cause the entire window to fall apart.
Additionally, it’s impossible to re-size, re-cut, or re-shape tempered glass once it has undergone the tempering process. All sizing must occur before the annealed glass is treated because once it is tempered, it is too susceptible to breakage to be cut or adjusted. Damage to any part of it will cause the entire glass sheet to shatter, so precision and custom installments are key to using tempered glass.
If these disadvantages sound like they may be a deal-breaker for you, know that there are other window treatments that provide a sound alternative to tempered glass.
Tempered Glass vs Film
One of the main alternatives to tempered glass is window film. In the tempered glass window film debate, window film tends to win out for a number of reasons. These multi-layer films significantly improve glass windows and doors’ protective capabilities, making them harder to penetrate, whether by forced entry or flying debris. They’re an unobtrusive and affordable way to hold glass shards together when the window is damaged, preventing the glass from harming those inside and slowing entry.
Safety & Security Window Films allow you to upgrade your glass to code for a fraction of the cost of a full glass replacement. Building codes may specify that glass near certain hazardous locations, such as wet surfaces, doors, floors, ramps, and stairs, meet certain safety glazing requirements. 3M Safety Window Films can help you quickly and easily meet safety glazing impact requirements for far less than the cost of replacement windows.
Window Film Depot is a certified installer of 3M Safety & Security Window Films. When you contact us, we’ll get a better understanding of your needs, schedule an onsite consultation, recommend the best products for you and discuss installation logistics.
There are many options to enhance window and door safety in both residential and commercial installations, so the decision comes down to what will best suit your needs. If you’re unsure, contact Window Film Depot and our representatives will do everything we can to guide you to the right product for you.
