Why Does a Small Chip Spread So Fast in Winter?

Hey folks! This is John from Freedom Auto Glass LLC.

Welcome to another Q&A session where I answer questions from you all on the internet.

Today's question is:

"Why Does a Small Chip Spread So Fast in Winter?"

Summary:

John attributes fast-spreading chips to temperature change. Glass handles rapid expansion and contraction poorly, particularly once it's already compromised by a chip. Sudden heat on a cold windshield — such as hot water or a blasting defroster — can worsen the damage, and the reverse, cold water on a hot windshield, will spread a crack as well. He identifies this rapid contraction and expansion as the most common reason chips become long cracks. Winter intensifies the problem because water seeps into the chip and freezes; as it freezes it expands, forcing the crack to grow. For these reasons, John strongly recommends repairing chips promptly, especially through cold Washington winters, before temperature swings and freezing moisture turn a small chip into a full crack.

Answer:

It comes down to temperature change. Glass doesn't do well with fast expansion and fast contraction, especially once it's already compromised by a chip. So picture a cold windshield, and then you blast it with hot water or crank the hot air from your defroster — that sudden heat is going to make the problem worse. Same thing the other way around: if you've got a hot windshield and you throw cold water on it, that'll spread the crack too. It's that fast contraction and expansion of the glass that does the damage, and it's the single most common reason these chips turn into long cracks. Winter makes it even worse, because water gets down into the chip and then freezes. When it freezes, it expands, and that expansion forces the crack to grow and spread out further. That's exactly why I always recommend getting a chip repaired sooner rather than later — the longer it sits, especially through our cold Washington winters, the more likely the temperature swings and freezing water are going to turn a small chip into a full crack.