What Causes Window Glass to Crack?

What Causes Window Glass to Crack?

Maybe your Pittsburgh windows are decades old, or maybe you just had new ones installed. Regardless, when you find yourself with a window that is cracked, it is less than ideal and may leave you scratching your head wondering, “What causes window glass to crack”? Most of the time, with a crack, and not a broken window, the cause is not apparent. We are going to review some of the most common causes that your window may have a newly discovered crack in it.

What Causes Window Glass to Crack?

When it comes to a broken Pittsburgh window, most of the time, the cause is evident; however, with a crack, it may be hard to pinpoint what exactly caused it. If you are asking yourself, “Why is my window cracked?”, we may have an answer for you below.

Let’s check out some of the most common causes of window glass cracking.

Stress cracks: If you find a crack near the edge of your window glass, it is likely a stress crack. Stress cracks are the most common types of cracks for window glass. Stress cracks are formed by continuous temperature changes and expansion and retraction of the glass. Think about a balloon on a cold day and how it shrinks, then think about bringing it inside your heated home and watching it expand. This happens over and over again to your windows, which can lead to the stress of the expansion overcoming the strength of the glass, causing a crack to form. Because we often have unpredictable and changing weather in Pittsburgh, stress cracks can be common.

Pressure cracks: Pressure cracks are less common and may seem to come out of nowhere. These types of cracks are mostly found in insulated glass and dual-pane windows. Unlike a stress crack that is usually at a perpendicular angle, pressure cracks generally form in the shape of a curve, kind of like an hourglass. Pressure cracks are also mainly caused by temperature and weather changes. Windows that are installed at too high or too low of an elevation level, or if there are drastic pressure system changes in the weather, can get pressure cracks caused by the buildup of pressure between the panes.

Impact cracks: While anything flying through the air that hits your window can cause it to break, that may not always be the case, and you could end up with just a crack. Impact cracks are caused by a flying rock, ball, birds, tree limbs, or other things that hit your windows hard enough to cause a crack, but not actually go all the way through them. Impact cracks can be identified by a center point (point of impact) and then have lines and cracks extending around it. These cracks are usually in a starburst pattern.

If you find your Pittsburgh windows with any type of crack in them, you should handle them as soon as possible. Cracks are known to spread and expand and can eventually lead to a full on break, which can not only mean you are letting the outside elements in, but could also be a safety hazard for your family.

At Residential Glass we are here for all of your Pittsburgh window needs. As Pittsburgh’s window and door repair specialists, we’re a trusted name in all things glass. From replacing broken panes of glass in storefront doors to installing new dual-pane windows for local homes, our team handles it all!

Need glass replaced or a window repaired? Contact us to set up a free estimate.

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