What are the Most Common Causes of Windshield Cracks?

Picture this: You are cruising along in your brand new car, but get stuck behind a slow-moving truck carrying construction material. You drive some distance behind the truck before pulling into the parking lot of a convenience store. After picking up some supplies, you come out and see something that stresses you out right away: a crack on your windshield. New car, damaged already, without getting into an accident! Ah, thats terrible. Is that even possible?


Well, it is possible. Windshield cracks are actually quite common. They can happen to new cars or old alike. You might think that an accident is the only reason for a windshield to crack, it is sturdy glass after all! But, that’s not always the case. Windshield cracks can happen for a variety of reasons. Many of these situations are avoidable if you exercise caution.


Loose Stones on the Road


This is one of the most common reasons for windshield cracks to appear. If you are driving on a bumpy road covered with loose stones or gravel, be careful. Loose stones can hit your windshield after coming under the car’s tires and can cause cracks in the glass if there is enough force.The type of crack most commonly caused by loose stones is a spider crack.


Other Vehicles


Yes, that’s right. Simply driving behind another vehicle or following trucks carrying materials too closely, can cause stones or loose debris to fall on your windshield and cause it to crack. You should take extra care while driving behind vehicles carrying construction material and keep a safe distance.




Weather conditions can have an impact on the windshield glass. The heat from a harsh summer sun can cause the windshield glass to expand. Extreme cold weather can make it contract. If the glass expands or contracts, it becomes more fragile and easily susceptible to cracks. In rainy weather, hailstones could be a problem that could cause significant damage.The same goes for chunky bits of ice when it is snowing.


Poor Quality Windshield

If the quality of the windshield glass is not good, it can crack easily. In this case, it might have to be replaced. When you replace your windshield, insist on OEM parts, so that you get  a part that will last long.


Improperly Fitted Windshield


Another reason for damage is if the windshield is not installed correctly, to begin with. If the glass is not fixed into place, it will shake when the car is in motion. This stress on the glass can result in cracks. If you notice this happening, get your automobile checked by a professional and get auto glass repair done right away. Avoid doing a DIY for replacing your windshield glass, instead, engage qualified glass technicians for the job, they will do it right the first time.


Change in Pressure


If you are driving up or down a mountain, the change in altitude, will cause changes in the air pressure.These air pressure changes can affect glass and lead to damage.

If the crack is small, a rock chip repair might be enough to fix the damage. More often than not, the only option to repair a cracked windshield is having to replace it entirely. If you are not covered by a warranty or insurance, windshield replacement can be an expensive affair.


Driving with a cracked windshield is very dangerous. It can affect visibility for the driver which could lead to accidents. It doesn’t take long for a small crack to grow bigger with movement or impact. If your windshield has a crack, albeit a small one, go for professional auto glass repair without delay.


How to Know When it’s Time to Get Your Windshield Fixed


Windshields are made of laminated safety glass. They consist of two curved sheets of glass with a vinyl plastic layer laminated between them, for safety purposes. During installation, the windshield is attached with an automotive grade urethane which creates a molecular bond between the glass and the vehicle.


Properly secured and cared for windshields also work as a safety device for protection, for the vehicle’s driver and occupants in case of a rollover accident.


Damage to windshield


The sun can weaken the strength of your windshield over time. Stones flung by wheels of passing vehicles or debris from rough weather can chip your windshield if the impact is forceful enough.


The chips can be so small that you might not even notice them. But, eventually can grow into a serious problem such as when water starts to trickle in through the cracks into the sensitive electric wiring of your car.




Some people use DIY kits to fix small chips on the windshield. Depending on the size and depth of the chip, this might temporarily help. However, if you are not experienced or sure about doing it yourself, it is better to have a professional take care of the damaged windshield.


Types of Damage


Impact of small objects such as pebbles on the windshield can be repaired or replaced, keeping the following things in mind:


  • Size – Cracks up to 2.4 inches can be repaired by an auto glass repair company while bigger cracks will require the windshield to be replaced. The need to replace or repair will also depend on acceptable state laws.


  • Type – Any damage near the edges or outer area of the windshield will need replacement as not doing so would affect the structural integrity of the windshield.


  • Depth -Small circular bulls eyes, rock chips, linear cracks, crack chips, dings, pits, and star shaped breaks can be repaired without replacing the windshield.


  • Location – Damage to the windshield on the inside, deep damage on both sides, on top of the rain sensor or internal radio antenna will need replacement of the windshield. Replacing the windshield is a good idea even for minor damages in front of the driver’s viewing area.


Complex multiple cracks, very large cracks, or cracks on the edges may need a windshield replacement.


A spider crack in a windshield- which has the appearance of a web – can be repaired if it is smaller than 12 inches diameter and has no holes.


What does Windshield Repair Involve?


For minor damages mentioned above, windshield repair involves removing air from the damaged area using a vacuum injection pump and injecting clear adhesive resin to replace the air inside the crack. The area is then cured with ultraviolet light.


When performed correctly by a professional auto glass repair technician, the damaged area’s strength is renewed along with clarity of 90-95% of the original glass.


What does Windshield Replacement involve?


Windshield replacement involves bonding the new windshield to the frame until it is strong enough to withstand the forces of a crash and prevent leaking. Under controlled conditions of temperature and humidity, the windshield is allowed to bond for the stipulated cure time.

You shouldn’t ignore even small damages to your windshield, as it can pose a serious threat to you and your loved ones in case of accidents. If you wait too long, it could cost you more as you might need a replacement windshield.


Contact Michael’s Glass Company for a free quote and get your windshield repaired as soon as you can. We’ll come to your home or have your car towed to our facilities and have your windshield replaced at the earliest convenience. For quotes or questions, call us at (215) 338-3293.