Types of Glass Breakage and How to Identify Them

Glass breakage can be dangerous, which indicates the glass should be replaced immediately to prevent it from shattering and potentially causing an injury. It’s best to identify the type of glass damage case by case, and there are various types of glass breakage.

It’s unsafe to leave broken glass untreated, so be sure to consult a glass expert like Reflect Window & Door. There are many situations that warrant a home or business to replace glass. Weather damage, accidents, new construction projects, home improvement projects, and other potential situations may require glass services.

Below are four types of glass breakage and how to identify them, in both commercial and residential settings.

Stress Cracks

Stress cracks start out near the edge of the window and spread from there. The cause of a stress crack is typically temperature-related, such as extreme heat or cold. Stress cracks occur in annealed or heat strengthened glass. To identify the difference between a stress crack and other glass breakage caused by edge damage, look for a chip at the edge of the glass – which is referred to as an “oyster.”

Impact Breakage

Impact breakage is caused by immediate impact, such as a ball thrown at a glass window at high speed. The pattern of the glass breakage is influenced by the speed of the object, as well as its size and thickness. A center point of impact breakage is formed during this type of glass damage, with lines forming around the perimeter going outwards.

Spontaneous Breakage

Spontaneous breakage refers to tempered glass breakage that seems to happen for no obvious reason, breaking on its own. There is always a reason, however, and it’s usually due to installation damage such as chipped glass edges. It’s a rare occurrence, but spontaneous breakage can also stem from nickel sulfide inclusions – a small rock that has remained in the glass and has the natural desire to return to its natural size, causing the glass to break as it expands.

Edge Damage

As mentioned above, edge damage happens with tempered glass breakage. It causes spontaneous breakage when the glass edges are compromised, for example chipped or nicked during installation, delivery or if the glass was cut into smaller panels.


If you’re ready to begin your glass replacement project, or you’d like to learn more about Reflect Window & Door, contact us today.