Stop the crack on your windshield from spreading (why and how)

January 31, 2023
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Windshield cracks can happen for various reasons, from rocks or falling branches to spring hail storms that damage your glass. No matter how it happens, a windshield crack can cause many problems for drivers. If your windshield is already cracked, there are a few ways to stop the crack from spreading before it becomes severe enough to require a professional.

You can stop a windshield crack from spreading by using a windshield repair kit or create DIY solutions using clear nail polish or superglue. Windshield cracks worsen when exposed to sudden temperature changes, excess vibrations, or moisture. 

If you’ve recently had a cracked windshield, here’s what you can do and why it’s so important to keep the glass intact.

Why Are Windshield Cracks Dangerous?

Windshields are the foremost defense for drivers against hazards on the road, like loose gravel and falling branches, but they also play a significant role in keeping those involved in major car accidents safe. Windshield cracks are dangerous for several reasons, one of which is that it hampers a driver’s visibility. 

An obstructed windshield is dangerous on the road, as a full range of visibility is necessary for safe driving, and massive cracks can obstruct vision, especially in low light or rough weather that is already difficult to navigate. This distraction can prove fatal in these weather conditions that already put drivers at risk of losing control of their vehicles. Also, cracks can reflect sunlight to create a blinding glare, distracting the driver and making it difficult to focus on the road. 

Windshield cracks can weaken the structural integrity of the windshield. Your windshield is partially responsible for the structural strength of the car’s roof, and cracks make it easier to break. If a vehicle with a weak windshield is involved in a rollover, the windshield may not be able to stop the roof from collapsing and causing injuries to passengers. It can also cause problems in a front-end collision if it cannot tolerate the impact.

Windshield glass is made from laminated glass, specially designed to ensure that it doesn’t shatter on impact. When laminated glass is punctured, it is meant to hold itself together as much as possible to prevent further cuts to the victim of a car accident. If the windshield is already cracked, the glass will likely split along those preexisting lines. If the glass shatters, it can cause injury to the driver and any passengers. 

During a crash, cars automatically deploy airbags, which bounce against the windshield with tremendous force before bouncing back toward those in the front of the vehicle. If your windshield is already damaged, the force of the airbag can cause it to shatter. Aside from putting you at risk of injury due to sharp glass, it also means that the airbag will continue out the windshield rather than bounce back toward you, effectively making the airbag’s cushioning useless and causing more injuries. 

How To Fix A Cracked Windshield

A crack in a windshield is a weakness that disrupts the pressure and weight distribution of the glass, and sealing it makes it more stable and less likely to put more stress on the other parts of the windshield. Minor damage like chipping can be dealt with at home – although it is possible to make quick DIY fixes with nail polish or super glue, a windshield repair kit will create stronger and longer-lasting bonds. These repair kits contain epoxy or acrylic adhesive fillers that you can use to fill in the crack. However, there may be a visible flaw left sometimes. These filler kits are not meant to be used on large cracks or holes, as they will not be effective. 

If you have a large crack, you can take your car to an auto shop that does glass servicing. Sometimes, they will not need to replace the entire windshield and instead use professional-grade tools to apply fillers. If the damage is too severe, they will order a new windshield for you to replace your damaged part. 

How To Stop Windshield Cracks From Getting Worse

Your first step after cracking your windshield should always be to seal it up in some way, 

whether it’s a small crack that you can fix with a kit or a serious one that needs professional help. Take this step to make sure that it does not spread. However, if you need to see a professional but must wait a few days, there are a few things you can avoid to ensure the cracks don’t get any worse before the appointment. 

Sudden Temperature Changes

Both extreme hot and cold weather can put extra stress on your windshield. If you live somewhere warm, make sure not to leave your car in the hot sun for too long and park in the shade whenever possible. The sun’s heat can cause the chips in the glass to travel vertically due to expansion. Cold weather can cause your windshield to bend into a slightly concave shape, causing the chips to spread horizontally.


Cold weather can also cause problems when there is excess moisture. If water seeps into the cracks and chips and then experiences cold enough temperatures, the water will freeze. As water freezes, it expands, and the water that has entered the cracks will do the same, causing further damage to the glass as the cracks to widen and deepen. 

Excess Vibrations 

Excessive shaking in a car can happen if you run over a pothole, slam your brakes or doors, or take a speed bump too fast. Even gravel and rocky terrain can worsen chips and cracks, as the vibrations and jarring can damage the windshield. 

For professionals interested in adding windshield repair services to their shops, the Elmo Anywhere point-of-sale payment software has an add-on for Glass Match Look-up for an extra $1 a month, or check out a total price break-down of the Elmo Anywhere software for more details.