Can a Cracked Windshield Shatter?


The short answer is yes, a cracked windshield can shatter. But there are several factors involved, and realize that using the word “shatter” may not be entirely accurate. Windshield glass is laminated, meaning it consists of two layers of glass with a thin plastic film between the layers. You may have heard it called “safety” glass, as its construction prevents the glass from breaking into more dangerous shards. It usually breaks into smaller pieces.

A windshield crack has the potential to grow as the glass expands and contracts due to temperature fluctuations, pressure applied to the glass, an object striking the glass, or dirt introduced to the crack. Any of these factors could worsen the crack – which has already weakened the glass – and cause it to “shatter.”

broken-windshield

But even if the glass does shatter, the likelihood of it collapsing into your vehicle or onto your hood, is unlikely. Windshields are held in place with strong urethane adhesives, which prevent leaks, noise and movement of the glass. Also, because the glass is laminated, the entire windshield generally won’t separate from the frame.

This doesn’t mean it’s safe to drive with a cracked windshield. Even a small crack means your windshield’s structural integrity has been compromised, which means it is now a safety hazard to you and your passengers. Even if the crack or chip is small, it’s important to have it checked out. You’ll need a qualified auto glass technician to help you determine if the glass can be repaired or if it should be replaced.

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How Long Can you Drive with that Windshield Crack?

Driving around with a cracked windshield is never a good idea be it for a long, or even short, period of time. When a crack happens it is best to start seeking out a reputable auto glass company sooner rather than later. You want to ensure the safety of you and those riding in your vehicle, and the windshield is an integral part of that safety system.

Chip or a Crack?

A windshield crack is different than a chip which can often be repaired. There are many forms of windshield damage though you’ll most often hear “chip” or “crack.” A chip is a general term that refers to small damage on a windshield, whereas a crack of damage is a distinct line that runs across the windshield. Check out more information on how to determine if a repair or replacement is necessary. Can a crack be repaired? Sometimes if it’s 14 inches or less and not in the driver’s field of vision. A trained repair technician will be able to judge if a repair will affect the vehicle’s operation. In that case, he or she will recommend a replacement.

Don’t Wait to Replace

If you have determined there is a crack that must be replaced, don’t wait. One of the most common problems with small cracks is that they tend to grow. Temperature plays a role here also, as changes can cause the glass to expand and contract. The crack creates a weak point in the glass, so why wait to get your windshield replaced?

How Long Does it Take for a Windshield Crack to Spread?

Moisture and Temperature

Your windshield is a glass sandwich—two pieces of glass with a layer of plastic in between—which means there’s room for moisture to get inside. When water gets through the crack it can weaken the entire windshield. If it’s cold enough, that water could also freeze, which could lead to even more cracks. Likewise, extreme temperature can also impact how quickly the crack spreads. Cold temperatures cause contraction—even in glass—and if it’s cracked or chipped the added pressure can cause further damage. The sun can also make the crack or chip worse, as it can increase the temperature of the windshield, causing the crack or chip to expand.

Dirt

Dirt can get inside the glass sandwich, which again can weaken the windshield. A temporary solution is placing clear tape over the crack until it is fixed. This doesn’t obstruct the view and can help keep dirt out.

Bumps in the Road

As much as you try to avoid bumps and dips in the road while driving, sometimes they can’t be missed. Unfortunately, this, too, can stress the windshield and cause cracks to spread. There may not be a specific length of time it takes for a crack to spread across the windshield, but the longer it’s there the more likely it will grow.

As soon as you notice the crack or chip, the best plan of action is to take it into an expert right away. You’ll find qualified technicians near you through Glass.com who can handle your windshield repair or replacement.

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21 responses to “Can a Cracked Windshield Shatter?”

  1. Thank you for info. Traveling and out of home state for 2 weeks and unable to repair until I return home. This article was helpful .

  2. What can happen if the orginating cracked started went around the front glass and has almost made a complete circle back to where it started?

  3. Thank you for this very informative post. I have a crack that started due to extreme temperature swings. It started out small but is spreading across the windshield. It will be fixed next weekend. I am hoping it holds up by then.

  4. My windshield started out with a small crack and is spreading across within minutes .. is that normal? Should I not drive it ? How long til it gets completely worse wont be able to get fixed til next weekend

    • Destiny,

      Yes- cracks can spread very quickly or very slowly and it depends on a great number of factors. Because of these numerous factors (temperatures, road conditions, etc.) it is impossible to say how long it will be before it gets worse. Our recommendation will always be to have a damaged windshield fixed as soon as possible because it is a safety concern. Many of our affiliate shops provide mobile service and can do the replacement at your home or work, which might help you get it done before the weekend. Either way, get in touch with a shop as soon as possible as they might need to order the glass.

      Drive safe!

  5. I purchased a used 2009 HHR, 89,000 miles in great condition. It didn’t have much freeway driving, but still had 6 tiny chips in the windshield. Now I see why! I drive 12 miles to & from work. Since Sept. I’ve been hit with four more rocks and a large piece of road debris that cracked a half moon in the upper right. Jeeps have nothing on this car. Tried to find a front spoiler, but there are none. It’s frustrating and dangerous. Poor safety design.

  6. Long shot here. I’m going to get my back window replaced in the morning. But I have to drive to the place to get it fixed. There is a huge hole where I’m guessing a ladder went through my window, but the sides are still in tact. Should I try to pull all of the glass out? Or drive and hope it doesn’t all fall out on my way?

    • Hi Stacie,

      Check with your local and state laws first to ensure it is legal, but the best option is probably to cover the opening with clear plastic sheeting. It will help keep out wind and debris while helping to keep the glass intact. It will distort your view, so be careful and use your side mirrors to your advantage.

      In the future, to save yourself the hassle (and danger) book with a shop that offers mobile service if there are any in your area.

    • Hi Craig,

      Thanks for the question! The best option will be to have a local qualified glass shop inspect the chip. They may be able to repair the windshield chip easily before it spreads.

  7. Traveling out of state with my family. Small crack from Thursday has already started to spread a good bit. Called AAA and they set us up with Safelite, who was supposed to come this morning to fix it at our hotel. They called this morning and said that our glass didn’t come in. 😐 Guess we’ll take our chances until we get home next week. Safelite guy said it should be fine and not to be concerned about the safety issue.

  8. Thank you for your INformation.. I called Autoglass and they told me it was safe to drive around with a crack in my windscreen on the drivers side until it can be repaired in a week! They said it was perfectly safe. I wonder if they have read information?,.

    • Hi Field,

      I’m not familiar with the shop you spoke with. We would never say that it’s “perfectly safe” to drive around with any amount of damage done to your windshield. At this point, its strength has been compromised, and so has your visibility. Hopefully the crack isn’t in your line of site and you don’t have to drive much between now and when it’s repaired!

  9. If you have a small crack on the passenger side and your car was sitting in heat will it make a new crack on the opposite side? Because the same crack on the passenger side is the same size.

    • Hi Ada,

      It is not common for symmetrical cracks to occur like this. More often, a single crack will spread from one side of the windshield to the other over time. It could be that there is stress or pressure occurring at that particular section of the windshield.

  10. I was looking at my car the other day to see that there was a crack on it. Finding a smash repair would be my best option and I would love to know how to keep it from spreading in the meantime. It was helpful to read that bumps can make it wider.

  11. My windscreen cracked this morning following a small stone that chipped the windscreen. I can barely feel the crack when brushing my nail across it on the outside. I would prefer to wait until the end of September to have this replaced, as my pay cheque is much higher that month. Is this non-advisable? Is it likely to worsen before then? Or is it safe to continue driving? If the crack does get substantially worse, I will obviously have to have it replaced sooner, but is this likely?

    • Thanks for the question, Lucy! We definitely advise getting the windshield looked at as son as possible. Depending on the size of the crack, you may be able to have the windshield repaired rather than replaced.

  12. Thanks for pointing out how windshield cracks tend to grow, and we should not wait to have it replaced. I am noticing a small crack at the bottom part of my windshield. It looks like someone threw a pebble at it pretty hard. To be sure I am not compromising my passengers’ safety, I will definitely go look at auto glass repair shops that can provide me with the necessary replacement.

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