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Windows are an integral part of our homes. They let us see the outside world, let natural light inside, and serve insulative and protective functions. If a broken window isn’t fixed quickly, it can let wind, rain, snow, or even insects into the home. Sometimes windows break without any obvious cause, which can be quite startling.
Causes of Broken Windows
Older home windows are more likely to crack or shatter because the glass is subjected to various types of stress over time. Weather, age, and sound waves act on glass and cause tiny fractures. Eventually, fractures grow or multiply until the glass breaks.
Sometimes unforeseeable accidents break home windows. Out of control balls or frisbees have caused the untimely demise of many windows, and over 100 million birds die every year after confrontations with windows. Unfortunately, some bird species are very territorial and try to fight with their own reflections. Objects hitting windows create impact cracks in a starburst pattern around a center point.
Double-paned windows with insulating glass have pressurized gas between two glass panels. Pressure cracks form in a curving pattern. The risk of cracks increases in windows installed at excessively high or low elevations. Drastic pressure changes due to weather can cause cracks in rare instances. It’s impossible to entirely prevent pressure cracks, but experienced professionals can install home windows with thicker panes and choose an appropriate type of glass for the climate and anticipated sun exposure.
Thermal Stress Cracks
Thermal stress cracks are one of the most common causes of broken windows in San Marcos, TX. A large difference between indoor and outdoor temperatures is known as a thermal gradient. Different areas of a glass pane contract or expand at different rates. A crack forms when thermal expansion becomes greater than glass strength. A thermal stress crack starts perpendicular to the pane’s edge and extends approximately a half-inch straight from the edge. After the first half-inch, the crack could go in any direction.
This is the same phenomenon that results in broken baking dishes when a dish is placed under cold water or put in the fridge too soon after removing it from an oven or stove. Any chip or weak spot may give way entirely under significant amounts of thermal stress.
Stress cracks are often related to the architectural design of your home, and they’re a greater risk to large windows underneath overhangs or located in recesses. Shaded areas of the window aren’t as susceptible to rapid heating and cooling as sunny areas, and the contrasting reactions to temperature result in thermal cracks.
Homeowners aren’t always aware of changes that could increase the risk to their home windows. Anything that changes the ratio of shaded to sunny areas around your home, such as the neighbor cutting down a large tree, could impact thermal stress on your windows. Other factors are entirely out of a homeowner’s control, such as extreme overnight temperature changes during spring or fall seasons.
Installing home windows isn’t as simple as it looks. Many factors must be taken into consideration, such as the home’s structure, window dimensions, pressure, stress, and temperature changes. Too much pressure on any section of a window increases the risk of shattering. Glass that isn’t fitted within the frame properly is much more likely to break than firmly placed panes. This actually happens frequently enough that it’s known as spontaneous glass breakage.
Broken glass is always a hazard. Safety glazing describes types of glass designed to reduce the risk of injury. It is often used for shower doors, skylights, sliding glass doors, and oven glass.
Tempered glass is up to 5 times stronger than conventional glass panes. It’s made through a process called quenching. Pre-cut glass panels are heated then cooled quickly. Outer surfaces are cooled faster than the center, which compresses the surfaces and edges while putting tension on the center of the glass panel. Instead of breaking into jagged shards, tempered glass shatters into tiny pebble-sized fragments.
Laminated glass is created by placing a layer of vinyl between two glass panes. The vinyl holds panes together if they’re broken. This type of glass is commonly used in vehicles, but it is gaining popularity in storefronts and home windows because it meets the requirements for hurricane-resistant glass.
Heated pre-cut glass cooled through a slower quenching process produces heat-strengthened glass. The slower quenching process means heat-strengthened glass has a lower compression strength than tempered glass, but it is still twice as strong as conventional glass.
Heat-strengthened glass isn’t actually safety glazing because it forms a jagged shard when it breaks. This type of glass meets safety standards for many applications if it’s combined with a laminated inner layer. Home windows made with heat-strengthened glass are resistant to thermal stress and withstand heavy snow loads as skylights.
Window frames are sometimes responsible for broken panes. Missing or out-of-place setting blocks, gaskets or edge blocks don’t provide proper stabilization and cushioning. Minor movement related to wind or temperature changes leads to surface damage and stress until the pane finally breaks.
Wooden window frames in older homes can also cause spontaneous breakage, although it isn’t really spontaneous. A wood frame deteriorates or shifts over time and doesn’t support window panels evenly. Uneven positioning puts stress on different parts of the glass that eventually break. Homeowners may not be aware of framing problems because the panes are only slightly uneven and tiny fractures around the window age often go unnoticed. A window may appear to break spontaneously when the break is actually a result of long-term factors. Hire professionals to install or replace home windows to minimize the risk of breakage due to frame issues.
Consult First Place Windows in San Marcos, TX, to choose the most appropriate type of replacement windows for your home. Experienced professionals install your new home windows correctly to make the most of your investment.