Heat Strengthened Glass

Compared with annealed glass, heat strengthened glass is typically about 1.5 to 2 times stronger.

Besides handling thermal loads better, it also shatters into smaller shards than annealed glass does. For this reason, it’s a safer alternative for homes or public buildings, as it poses less of a risk to residents. 

That’s why it’s a great choice for large areas of glazing where one part of the glass may be in direct sunlight while another is shaded. That uneven heating can put stress on glass, so heat treated glass is designed to cope better with this temperature difference. 

Heat-strengthened laminated glass provides the perfect balance between safety and thermal performance. 

• Better retention if breakage happens: The interlayer is designed to hold the broken pieces in place, so the pane is far less likely to fall away. This is ideal for commercial buildings, entrances, screens, and certain overhead or high-level glazing. 
• Improved temperature resistance: Because the base glass is heat strengthened glass it’s commonly chosen for glazing that may see uneven heating across the pane.
• Breaks into larger pieces: This type of strengthened glass tends to break into larger pieces than fully toughened glass. In laminated form, this can help the pane remain more intact and “hold together” in a more predictable way.
• A practical choice for large panes and architectural glazing: It’s a great choice for façades and other large glazed areas where the project needs a combination of strength, safety performance (via lamination), and thermal reliability.

Heat-soaked glass is glass that’s undergone heat-soak testing, a quality-control step typically associated with toughened glass. 

This process is designed to reduce the risk of rare spontaneous breakage caused by nickel sulphide inclusions by heating the glass to 290°C for 2 hours. As a result, the glass is as strong as fully tempered glass and is used for high-risk installations, like balutsrades or high rises. 

On the other hand, heat treated glass undergoes thermal processing by heating it to a lower temperature than fully tempered glass and allowing it to slowly cool. This isn’t as strong as fully tempered glass, but it’s ideal for custom laminated glass applications. 

In the UK, strengthened glass is defined in accordance with BS EN 1863-1.

What’s the difference between heated glass and heat treated glass?

Heat-treated glass is simply glass that has undergone the furnace-heating cycle to improve strength and thermal resistance. 

Heated glass, however, is an electrically heated unit used for demisting, condensation control, or home heating.

For example, our GLOW products are electrically heated glass units where power is converted into radiant heat within a sealed unit. Once installed, it provides a direct source of warmth to people and objects in a home, offering a more controlled heating system.

On its own, heat-strengthened glass isn’t normally treated the same way as toughened safety glass because it breaks into bigger fragments than fully tempered glass. 

So if the project requires a safety solution, fully tempered glass is more suitable. 

That’s where heat-strengthened laminated glass comes in. The interlayer is there to hold the glass together if it breaks, helping manage fallout and maintaining a barrier.