What are tempered glass windows?

Tempered glass windows are windows that have been treated with high volumes of heat, and then quickly cooled to create extra-strong glass. By being treated in this way, tempered glass is a minimum 4x stronger than float glass and crumbles into small pieces when broken to reduce the risk of injury.

All of our roof windows are made with tempered external glass.

Is there a difference between tempered glass and toughened glass?

Tempered glass and toughened glass are the same type of safety glass. Both aptly named, mean glass that has been treated by the increasing then lowering of its temperature to increase the strength of glass.

How is tempered glass made?

Tempered glass is made by treating float glass with high volumes of heat, and then cooling the glass quickly. As the outer layers get cool, the inner layers remain hot and begin to pull away from the outer layers, creating tension. The outer layers then go into a process called compression. Both of these processes give you the strength of tempered glass, and its important shattering feature.

What else is tempered glass used for?

Tempered glass is used for a wide variety of household and industrial items including windows, phone protectors, oven doors and more.

The history of tempered glass

Tempered glass has been used in multiple ways over the last 150 years, but did you know the potential discovery of tempered glass had amusing beginnings?

It is said that in the 17th century, Prince Rupert of the Rhine was introduced to a peculiar object that were shaped like a teardrop made of glass and were aptly named “Prince Rupert’s Drops” after the prince gifted them to King Charles II.

These drops were created by dropping molten glass into a bucket of water and unintentionally copying the tempering process. What made these drops interesting is that the body of the drop could withstand a strike of a hammer, but if the tail was damaged, the entire drop would explode and shatter. The pebbles that remain would resemble broken tempered glass or safety glass.

However, this story has been disputed by some historians, who say that glassmakers have known about these tempered glass drops since the Roman Empire!

Advantages of tempered glass

There are many advantages of tempered glass, including household appliances as well as safety uses.

Household Uses

As tempered glass is stronger than normal glass, items around the home such as glass doors and glass tables are typically made from tempered glass. It improves the strength of these items as well as making them safer to use.

If a tempered glass table or door did break, the glass would shatter into small pebbles instead of harmful shards of glass, making the glass safer in the event of a break.

Food & Drink Industry

In the food and drink industry, tempered glass is used for numerous products and gadgets, including kitchen splashbacks, glassware and microwave windows.

As tempered glass is stronger than normal glass, window panes that are used in oven doors are typically made from tempered glass. This means that the oven window is harder to crack and has heat-resistant qualities.

Safety Breakage

A great benefit of tempered glass is the way it shatters. When a typical glass window or pane is broken, you will be left with large shards of glass that can be harmful and difficult to handle. Meanwhile, when tempered glass breaks, it will shatter into small pebbles, minimising the chance of someone getting hurt.


Tougher than traditional glass

Tempered glass is a minimum 4x tougher than traditional glass, which makes it the perfect fit for jobs that require strong, more resilient glass.

A great use of tempered glass would be the windscreen of a car, for example, or one of Dakea’s Ultima Energy roof windows that use 6 mm of toughened glass. This has been combined with laminated glass in the inside, giving Dakea windows a safety glazing construction.

Roof Windows

Dakea’s collections of roof windows have incorporated tempered glass to improve window safety.

For more information regarding our products, feel free to contact us today.

Related articles


How to open skylight windows

This is primarily a guide on how to open skylight windows from Dakea. If you’re looking for information on ... read more

Windows two open roof windows

Roof Window Types

Learn the different types of roof window with this guide. read more

Flashing roofers replacing a roof

What is Skylight Flashing?

Skylight flashings are designed to provide the weatherproofing junction between the roof window or skylight... read more

Join our newsletter!

Are you a professional installer, contractor, or housebuilder? Sign up for our newsletter today to be the first to hear about new products, promotions and exclusive offers.

For all other enquiries please complete our contact form on our website.