Window cracks are best addressed directly by a glazier.
If a crack does appear, addressing it quickly can prevent further damage. Give our friendly team a call if you require recommendation for local glaziers.
Window Cracks Explained: What Happened?
Common Causes of Window Cracks
Thermal Stress Cracks
Caused by sudden temperature changes, such as extreme heat on one side of the glass while the other side remains cool.
Common in windows exposed to direct sunlight or near heating vents.
Impact Cracks
Result from objects hitting the window, such as a rock, cricket balls, or a bird.
Typically has a distinct impact point with spiderweb-like cracks spreading outward.
Pressure Cracks
Occur due to changes in atmospheric pressure, often in double-pane windows.
Common in high altitudes or areas with extreme weather shifts.
Appear as curved or wave-like cracks.
Structural Stress Cracks
Happen when a building shifts due to foundation movement, improper window installation, or settling over time.
Often start from the edges and spread inward.
Poor Installation or Manufacturing Defects
If a window is not installed correctly or has a manufacturing flaw, it may develop stress points that lead to cracks.
Manufacturing defects are a rare occurrence and may be covered under warranty following assessment.
AGP products meet all statutory warranty requirements and are fully tested to ensure compliance with the New Zealand Building Code. There are some simple things you can do to help retain their appeal for many years to come.
