When you’re faced with a broken window or glass pane, the immediate aftermath can be stressful, especially if you’re worried about who’s responsible for the repair. Landlords often expect tenants to cover damages, but what if the glass broke without any apparent cause?
On a larger scale, managers or owners of large properties can be stymied by a succession of seemingly spontaneous glass breaks that occur, even in relatively new buildings. These large-scale situations have broad implications: pedestrian safety, resident safety, loss of revenue and the need to mitigate future risk.
Understanding why glass breaks and how to properly document it is crucial for managing costs and planning next steps. This guide will walk you through the essential steps to document glass breakage, providing you with the evidence needed to determine the cause and have the appropriate party pay for the repair.
Why Did My Glass Break? Understanding Common Causes
The sudden, unexpected breakage of glass can be baffling. While it might seem like “nobody touched it,” glass breakage is almost always due to a specific cause, even if it’s not immediately obvious. Here are some of the most common reasons why glass breaks:
Spontaneous Glass Breakage Due to Thermal Stress
Differential heating or cooling of glass, in older or newer installations, can create stress and lead to cracks. Direct sunlight on one part of a glass pane while another part of the same pane is shaded causes uneven expansion. A temperature differential of 50°F across the pane can break annealed glass. Such fractures emanate from an edge, then meander across in one or more cracks. Uneven heat on the inside can produce the same effect. There have been instances where insulation, draperies or even pets (!) that partially insulate the glass from the room heat on a very cold day can elicit thermal glass breakage.
Spontaneous Glass Breakage Due to Nickel Sulfide Inclusion
Nickel sulfide inclusions can cause spontaneous breakage in tempered glass. These tiny stones are placed in a state of compression during the tempering process. Eventually they break the entire pane in an instant. After breakage, the inclusions can be seen at the common border between two polygonal-shaped particles. This pattern is sometimes called a butterfly pattern.
Impact
This cause of glass breakage is well known. An object hitting the glass, whether it’s a thrown ball, a bird, a rock from a lawnmower, or even a shoulder bump, can break glass. The impact point, also called the fracture origin, is often evident. It can look like the hub of a spoked wheel. The cracks that emanate from the hub are called radial cracks. Sometimes another set of cracks occur, called circular cracks, that occur as a larger circle with the fracture origin as its center.
Improper Installation or Glazing
If glass isn’t installed correctly, it can be under constant stress from the frame. Too much pressure, uneven support, or direct contact with hard materials can lead to breakage over time. Glass is supposed to be set on two hard rubber setting blocks at the quarter points beneath the glass. The sides and top need a bit of room, or if they are touched by something, it should only be setting blocks. Insulating glass consists of two panes of glass sandwiched onto a spacer that goes round all four edges of the glass. If the setting blocks only support one of the panes rather than supporting both, failure or breakage can occur.
Frame Movement/Building Settlement
Buildings naturally settle and shift over time. This movement can put stress on window frames and, consequently, on the glass panes they hold, leading to fracture.
Pressure Differences
Extreme pressure differences between the environment and the pressure inside the insulating unit can sometimes cause glass to break. This might occur if insulated units are transported, for example, from low plains to high mountains or vice versa. Breather tubes are sometimes used to equalize the pressure, but these come with their own set of problems. Another unexpected source of pressure differentials between ambient and airspace occur when argon gas that was filled in the airspace leaks out but is not replaced by air due to the permeability of the spacer sealants. This issue is called argon depletion.
Defects in the Glass
Manufacturing defects, such as bubbles or inclusions (like the aforementioned nickel sulfide), can weaken the glass and make it more susceptible to breakage under normal conditions. Edge damage can devolve into full fracture over time. Edge damage can occur in the factory, during transport or during installation.
How to Document Glass Breakage: Your Essential Guide
When glass breaks, thorough documentation is your best course of action. This evidence is crucial for a glass expert to analyze the breakage pattern and determine the root cause, potentially helping to assist in allocating responsibility and planning for future mitigation.
Take Immediate Pictures of the Glass Breakage
The first and most critical step is to photographically capture the scene immediately. Evidence can disappear or degrade quickly. Use the highest quality settings on your camera or smartphone. If using a smartphone, email the photos to yourself or an expert rather than texting, as texting often compresses images and reduces their resolution, which can obscure crucial details.
Wide Shot
Stand back and take comprehensive pictures from both sides of the glass. These photos should include the entire area surrounding the broken glass. If there are any obstructions like curtains, blinds, or furniture, first photograph the scene with these items in place, then move them and take additional pictures. This provides context for the breakage.
Medium Shot
This shot should capture the entire piece of glass in one frame. It’s perfectly acceptable to rotate your camera sideways to get the best fit. The goal here is to show the overall breakage pattern and the general location of the focal point of the glass breakage.
Closeup of Focal Point
When glass breaks, the cracks almost always emanate from a specific origin point, known as the focal point. Locate this area and take very detailed close-up photos, focusing on a 3″ x 3″ section around it.
First, hold your camera perpendicular to the glass and shoot directly at the focal point.
Then, hold the camera at an angle of about 45 degrees to the side and shoot the focal point.
Repeat this angled shot from both sides, from the top, and the bottom of the focal point. These varied angles can reveal subtle characteristics of the break that indicate its cause.
Preserve the Focal Point of the Glass Break
After you’ve taken your documentary pictures, it’s vital to preserve the most important piece of evidence: the focal point of the glass break.
Immediately place clear tape over the 3″ x 3″ focal area. 2-inch wide clear packing tape is ideal if you have it readily available.
When the glass is eventually replaced or cleaned up, carefully remove and keep this taped section of glass.
If the tape is on the interior side of the glass, use a marker to write “interior” on the tape. If it’s on the exterior, write “exterior.”
Place this preserved piece of glass into an envelope. This envelope should also contain a piece of paper with all the detailed documentation described in the next step.
Document Glass Breakage Facts
Beyond the visual evidence, written documentation provides crucial context and can help establish a timeline.
Record the exact date and time the glass breakage occurred.
Note the direction of exposure of the glass (e.g., “north-facing window,” “west-facing patio door”). This is important for understanding thermal stress.
If you know it, write down when the glass was installed or its general age. Also, note who provided or installed it. This information can be vital if there’s a history of similar issues or if the installation quality is questionable.
For larger properties or buildings, it’s particularly important to preserve information about glass breakage events over long periods. Sometimes, what seems like an isolated incident can actually be part of a larger pattern or “epidemic” of glass breakage, indicating a systemic issue.
In a Nutshell
By following these steps, you’ll gather comprehensive evidence that can significantly help a glass expert determine why your glass broke and what to do about it.
This proactive approach empowers you with the information you need to discuss responsibility with stakeholders and providers, ensuring that the proper party takes responsibility.
Contact us if you need help with glass breakage.
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