A thermal fracture is a glass fracture that appears seemingly without cause. There was no impact at all on your glass and yet you are left with a fracture. A thermal fracture is caused by temperature differences in your window unit. This stresses the glass, resulting in a very recognisable crack. You see a fracture line perpendicular to the edge of the window, branching out into hairline cracks.
A typical cause of a thermal fracture is a roller shutter or screen that is not fully lowered or raised. Especially in summer, the glass heats up unevenly. This causes stress on the glass, resulting in a thermal fracture.
 

We would like to give you some tips to avoid these annoying and costly fractures:

1. Always raise or lower your screens and shutters all the way
2. Do not stick posters or dark stickers on the glass
3. Do not place large objects, such as stuffed animals or big chairs, in front of or against the window
4. Do not place heating elements, e.g. patio heaters or radiant heaters, near the glass
5. Do not spray warm glass with cold water or cold glass with warm water