Can Your Windshield Shatter for No Reason?
Some say it is an urban legend that your windshield can “spontaneously shatter.” So, what is the truth? Well, it is not so black and white. Older windshield glass was made in a different way than how today’s windshield glass is made so it was more common or possible with old windshield glass (which still may be on your car if you drive an old or vintage car). Today’s windshield glass is laminated, tempered safety glass that has been designed to be “shatter proof.” And, while today’s glass significantly improved there are ways for your glass can spontaneously shatter.
To clarify – your windshield will not really “spontaneously” shatter just from high heat or extreme cold. The process is more gradual than spontaneous. If you have a crack in your windshield that you do not have repaired and the seasons change you are at an increased risk of having your windshield spontaneously break. What happens is that when your cracked windshield experiences extreme temperatures it expands and contracts and therefore the crack grows. If it grows too much, the windshield will break. Your Mechanic explains how cold temperatures impact cracked windshields, “Extreme cold temperatures cause everything to contract. Metal, rubber, sealant, and even glass are subject to expansion and contraction in any temperature difference… If your glass is chipped or cracked, the extra pressure on the glass can cause your window or windshield to crack or shatter, though it is more common for cracks to form than for the window to shatter. The crack will typically form from the point of weakness and extend towards the edge, but not always.”
And, just like extreme cold temperatures cause cracks to grow which could lead to a windshield shattering, extreme heat can do the same thing. That is why it is important to get small cracks and chips repaired as soon as possible. Those small cracks and chips can often be easily repaired for a minimal cost. But, if they are left unrepaired, what started as a small star on the windshield can rapidly grow to a major crack in extreme temperature or when major temperature shifts occur. When this happens, a complete windshield replacement will be necessary. Though your windshield probably won’t spontaneously shatter all over you, large cracks are not only unsightly but dangerous and costly. Get small cracks or chips repaired as soon as possible to avoid them growing and potentially causing yoru windshield to break completely.