Windshield Repair: The Things You Need To Know

You might be surprised to learn that a car windshield is comprised of three layers -- generally, two pieces of glass with a thin layer of polyvinyl butyrate between them. Polyvinyl butyrate, or "PVB," is a sheet of resilient plastic film that essentially holds the glass pieces together. If the outer glass layer is struck by a rock or other debris, the glass might flex and chip or crack. A rock chip is the most common type of damage, and it can form a star shape, a radiating bullseye or a crack.

Watch Out -- Chips Can Grow

Although a small chip in your windshield can seem minor, it will probably eventually form a crack. Studies have shown that 90% or more of windshield chips turn into cracks, which then continue to grow larger. Temperature changes and bumpy roads are just some of the factors that can cause fatigue stress to the original damage and cause it to spread.

Stopping Cracks in Their Tracks

The science of crack repair has changed and evolved over the years, but the method is the same: to substitute the air within the crack or chip completely with acrylic resin. This process serves to prevent further damage, restore the structural integrity of the windshield and also improve visual clarity for the driver. Windshield repair is generally at least attempted before a windshield is replaced, especially if the damage is minor.

When It's Time for a New Windshield

If a rock chip spreads to become a larger crack, windshield repair is less viable. A new windshield can cost anywhere from $300 to over $1000, depending upon the type of vehicle and replacement windshield required. Windshields bought from the original manufacturer tend to be much more expensive than aftermarket versions. Add-ons like sun coatings, heating elements and antennae increase the cost even more.

Some Concerns and Considerations

When a windshield is replaced, make sure the installer gets as close to the original factory seal as possible. While it will never be quite the same, a good installer can come close. A quality seal is important for a variety of reasons, including preserving the structural integrity of the car.

Disposed windshields have an environmental impact as well. About 15 million windshields are replaced each year in the U.S. alone -- that's 600 million pounds of waste. Much of the waste ends up in landfills, although that is starting to change as more eco-friendly measures are employed.

You may not give your car windshield much thought, but if you ever have to deal with windshield repair or replacement, now you're up to speed on the basics!