What is Tempered Glass?
Tempered glass, also known as toughened glass, is safer and stronger than annealed or regular glass. The manufacturing process involves altering the glass’s properties. When tempered glass breaks, it shatters into little granular pieces instead of sharp shards. This minimizes the risk of injuries and damage caused by broken glass.
For safety reasons, most interior and exterior windows should be glazed with tempered glass especially if they are close to doors where traffic is high.
Why Use Tempered Glass?
There are several reasons why tempered glass is widely used.
Strength and Durability
Toughened glass is four to five times stronger than conventional glass, making it a safer choice for your projects. It can withstand higher levels of force, making it less likely to break or shatter.
Regular glass, also known as annealed glass, can be hazardous when it breaks, leaving behind sharp pieces and very small slivers that can cut. In contrast, tempered glass breaks into small and relatively safe pieces.
Tempered glass has excellent resistance to thermal stress and extreme heating. It can withstand high temperatures without cracking or breaking, so it is used for kitchen appliances, like oven doors, fireplace enclosures, and glass cooktops.
Building codes and regulations often require the use of tempered glass for safety reasons. For example, in residential buildings, you must use tempered glass where there is a risk of human impact, such as the areas close to doors, stairways, or shower enclosures.
Tempered glass undergoes a controlled manufacturing process involving heating and rapid cooling. This creates internal stresses that increase its strength.
A Comparison of Annealed and Laminated Glass
Tempered glass is commonly used in commercial applications, especially for exterior glass storefronts, doors, and windows. Thermal tempering strengthens the glass, protecting against breakage and customer and employee injuries. While tempered glass may appear similar to annealed glass, it is considerably stronger and, although it may cost more, it is a better choice when safety is a concern.
A professional glass company, like California Window Glass, understands the regulations and requirements for tempered glass windows. They’ll ensure that the appropriate glass is used for your project.
Tempering for Enhanced Breakage Resistance
Tempered safety glass is the most suitable option for commercial projects with exterior windows, doors, or storefronts. In areas prone to extreme weather, like strong winds, storms, or extreme temperatures, regular glass could break, posing a danger for employees and customers. The sharp points associated with regular glass breakage are a significant concern for homeowners and business owners. These are avoided with tempered glass.
The International Residential Code establishes building codes that dictate where safety glass should be used in homes to prevent injuries or fatalities.
The Glass Tempering Process
During the glass tempering process conventional glass is cut to size and then exposed to intense heating followed by rapid cooling. This controlled thermal treatment alters the physical properties of the glass, resulting in tempered glass with enhanced strength and safety characteristics.
The cut glass is processed through a furnace, where it is heated to a very high temperature, typically around 600-700 degrees Celsius (1112-1292 degrees Fahrenheit). The exact temperature and heating time depend on the thickness and type of glass being tempered.
After the glass reaches the desired temperature, it is rapidly cooled using jets of high-pressure air. Known as quenching, the rapid cooling creates a state of high compressive stress on the glass’s outer layers, while the inside remains under tension.
This gives the tempered glass its increased strength and impact resistance. If the tempered glass does break, it will completely shatter into small, relatively harmless pieces with rounded edges instead of sharp, hazardous shards.
Once the glass passes inspection, it is ready to be used in various applications where strength and safety are essential, such as windows, doors, shower enclosures, and automotive glass.
Once the tempering process is complete, the glass cannot be cut or altered without risking its structural integrity.
Uses of Tempered Glass in Residential Settings
Toughened glass finds various applications within households.
Glass doors, whether fixed, swinging, sliding, bi-fold, or standard, should have tempered or laminated glass installed. Laminated glass is commonly used in windshields and skylights. Laminated glass consists of two glass layers with an inner layer that improves sound insulation and can help block UV rays. Laminated glass is an alternative option for exterior windows, storefronts, and curtain walls.
Working with a professional glass company like California Window Glass ensures that you receive proper guidance regarding the differences between laminated and tempered glass, including cost and application variations. Californa Window Glass guarantees its products and installation.
Tempered Glass Applications
Tempered glass is used in various contexts, such as:
- Balcony doors
- Athletic facilities
- Swimming pools
- Shower doors and bathroom areas
- Exhibition areas and displays
- Unframed assemblies in buildings (e.g., frameless glass doors)
- Structurally loaded applications
- Situations where human impact could be dangerous, such as some skylights, glass near doorways and stairways, large windows, floor-level windows, sliding doors, elevators, and glass near swimming pools.
Security window films, placed over the entire window can add additional strength to commercial windows and can protect your business from forced entry and illegal access as these films prevent the glass from collapsing.