Car Glass Damage: Common Causes, Types, and Tips for Repair

Windshields are far more important than most car owners realize. They are a crucial part of a vehicle’s safety restraint system and do much more than simply shield the cabin from external elements such as dust, bugs, rain, wind, and stones.

Windshields also serve key safety functions by:

  • Allowing airbags to deploy in the correct direction
  • Providing structural integrity to the vehicle’s roof during a rollover
  • Displacing kinetic energy during a front-end collision
  • Preventing the driver and passengers from getting ejected during a collision

Car glass damage impedes your windshield’s ability to fulfill these life-saving functions. In modern cars, glass damage may even hinder the functionality and reliability of some driver assistance functions.

Windshields also play a more important role in modern cars. They also house sensors — working with onboard computers, cameras, radar, and LIDAR — that help operate Advanced Driver Assistance Systems (ADAS). It’s why auto glass repair is a task best left to professionals who not only repair or replace windshields but also calibrate ADAS components.

Common Causes of Glass Damage

Auto Glass is glass, and glass can break. Understanding the conditions that can damage your glass can help you identify the times that require greater vigilance. If your vehicle has been exposed to these conditions, you may need to check your windshield for damage.

Adverse Weather Conditions

Gusty winds, extreme temperatures, and hail storms all present conditions that can damage your windshield. Gusty winds from tornados and hurricanes can turn debris into projectiles that can damage your windshield, while major hail storms can create hail big and heavy enough to crack windshields.

Extreme temperatures can alter the structural properties of glass (extreme heat expands molecules while extreme cold compresses molecules). So rapid and extreme temperature changes can crack your windshield.

Kinetic Damage From Road Hazards and Car Accidents

Debris will always find a way onto roads. Rocks and gravel can damage or crack your windshield with enough kinetic force. They are especially common on highways where high speeds increase the force of impact.

Car accidents yield more than enough kinetic force to damage your windshield and are among the most common causes of glass damage. An extreme impact force damaging the vehicle structure can create fractures in glass or worsen those already present before the accident. Generally, you should always inspect your windshield for any damage following a car accident.

During a vehicle crash, airbag deployments use the windshield as a backboard to protect occupants. Airbag deployments can damage windshields, especially in the steering wheel and passenger side dash.

Types of Automotive Glass

Glass has different compositions and undergoes different manufacturing processes. Auto glass is either laminated or tempered. Tempered glass is predominately used for car windows and rear glass. Laminated glass is always used for windshields and may be found throughout the vehicle.

Tempered or safety glass is designed to withstand strong impact and shatter into small pieces with rounded edges.

Laminated glass is designed to be sturdier and to be used as part of a vehicle’s structural integrity as it has two pieces of matched glass bonded with a clear plastic film — the Polyvinyl butyrate (PVB) interlayer — in between. This type of glass is designed to keep broken glass together and to provide a barrier preventing occupants from ejection during a collision.

Types of Auto Glass Damage

Learning to identify the types of car glass damage matters because it’s a quick way to determine whether a glass panel can be repaired or needs to be entirely replaced.

Minor Chips

Minor chips are among the most common types of windshield damage. However, their repairability mostly depends on chip size, location, and depth.

Skilled technicians can repair most chips smaller than 40mm across and confined to the windshield’s outer layer. Minor chips should be immediately repaired because they can spread out further and diminish the structural integrity of your windshield.

Some minor chips include the following:

Star Break: A star-shaped chip with cracks of varying lengths spreading from the point of impact.

Half Moon: Distinct from the half-circle that stems from the point of impact.

Clover Leaf: A circular chip that resembles a clover leaf. Cloverleaf chips are indicative of the separation of glass layers. (Laminated glass)

Bullseye: The Bullseye is the most common chip type. Distinct for its small size, the pit at the point of impact, and a circular break surrounding the pit.

Combination Break

Glass damage can also feature different types of cracks within the chip area. They are a combination of the previously mentioned chip types. Combination breaks will often require a skilled technician to repair or determine if repair is possible or if it needs to be replaced.

 

Technicians can only repair a combination of up to three chips per windshield as long as none are in the driver’s direct line of vision. Three or more chips in total will warrant a windshield replacement.

Irreparable Damage

Certain damage requires a windshield replacement because of severe damage that could affect the structural integrity of the glass or affect the driver’s vision. Damages — cracks or any chips that are located in the driver’s line of vision — are subject to state and local laws. While it may seem like an overreaction to most people, replacing a windshield because of a few chips is a preventive measure meant to avert an accident.

Conditions that call for a windshield replacement are:

  • The chip exceeds the size of a quarter in diameter
  • A crack outside of the driver's vision exceeds 6 inches
  • Damage penetrates both layers of the windshield
  • The chip or crack obstructs the driver’s line of vision
  • Windshield crack begins or ends at the edge of the windshield. (Compromises glass integrity)

The PVB layer is compromised. (The PVB layer prevents the windshield from shattering into sharp glass shards that can cut vehicle occupants.)

The Dangers of Damaged Car Glass

Driving with damaged car glass may not seem dangerous until you’re in a collision. Your vehicle’s windshield is a vital part of a safety system meant to mitigate the risk of injury or death in case of an accident.

Obstruction of Vision

The most apparent function of a windshield is that it provides drivers with a clear view of the road. A chip or crack can obstruct your view, hindering your ability to identify and respond to dangers on the road.

Sharp Shattered Glass Shards

The PVB interlayer is what makes laminated glass shatter-resistant. As a result, driving with a compromised PVB interlayer is extremely dangerous.

You risk having your windshield shatter into sharp shards under excessive pressure, heat, and kinetic force. It’s even scarier when considering that the driver and front passenger would be exposed to the glass shards.

Car Glass Repair and Replacement Options

Damaged car glass poses a significant safety risk. Even when some types of glass damage are repairable, they gradually worsen until they can only be addressed through a windshield replacement.

If you have a damaged windshield, here are some options:

Windshield Chip Repair: Professionals favor using a repair resin that is injected into the affected area. Windshield resin will fill in gaps in chips and cracks and also help strengthen the damaged area.

Windshield Replacement: It involves removing and replacing the damaged windshield with a new one. A windshield replacement in modern cars with ADAS systems involves calibrating crash avoidance sensors.

Factors That Influence Car Glass Repair or Replacement Costs

Damage Type: The nature of your windshield damage will determine whether you qualify for a repair or have no choice but to opt for a replacement.

Vehicle Make and Model: Vehicles have different features based on make and model. Even different vehicle models from the same manufacturer could have variations in glass manufacturing. These features add to the cost of the glass for consumers. Supply and demand also control the pricing of products being sold in any market. Common vehicles have lower stabilized prices. Exotics are usually more expensive due to lower demand.

Insurance Coverage: Your insurance coverage is one of the biggest factors because it determines how much you’ll have to pay out-of-pocket (if at all). If you have comprehensive collision insurance, your policy will likely cover windshield repair or replacement.

Car Glass Damage Prevention Tips

Preventing car glass damage entails avoiding certain conditions. These simple measures can help keep your windshield damage-free, while some will help you avoid car accidents altogether:

  • Avoid Tailgating
  • Park Under Cover or in a Garage
  • Remove Ice Using a Plastic Scraper, Windshield Wipers, and Defroster
  • Avoid Tailing Trucks Hauling Gravel
  • Avoid Introducing Sudden Temperature Changes

What Should I Do in Case of Car Glass Damage?

Many conditions can damage your windshield. While a damaged windshield may not seem pressing, it’s an issue that only worsens when ignored.

Here are the steps to take If you notice a chip or crack in your windshield:

Assess the Damage

Assessing the damage lets you ascertain its severity and whether it requires immediate attention. Depending on the type of damage and its location, it could result in a glass replacement instead of a repair.

Call for Assistance

If the damage to your windshield is severe enough to spread or become worse, it’s best to call a trusted repair center for assistance. It’s always best to err on the side of safety.

Hire Professionals to Repair or Replace Your Windshield

Auto glass repair is not a task you can do on your own effectively. The limitations of DIY windshield repair kits, the ever-worsening damage, and the need to calibrate ADAS sensors in newer models make a professional auto glass repair or replacement service the best use of your time and money.

Windshield repairs are not a matter to be taken lightly, so you should only entrust these repairs to reputable service providers like Caliber Auto Glass.