Fiberglass has been used for years to create strong, lightweight items like canoes and skis. Over the last few decades, it’s also become a popular material for window frames. But, if you’re shopping for replacement windows for your home, you may be wondering about the difference between vinyl and fiberglass. Here’s a general overview:
Fiberglass windows are made from a material similar that of car bumpers, making them strong and maintenance-free. They’re manufactured by pulling, or pultruding, polyester resins containing strands of glass through a die that’s been heated. This result is called a lineal, which can be shaped and machined.
Compared to vinyl, fiberglass windows are the strongest. In fact, they can be as much as 9 times as strong as vinyl frames. For the most part, fiberglass frames are also more impact-resistant than any other type of replacement windows.
Both resist rot and pests like carpenter ants and termites, but fiberglass windows are more durable overall than vinyl. Generally, fiberglass windows will last nearly 40% longer than vinyl ones. Because they’re made from glass, fiberglass frames contract at expand at about the same rate as window glass with temperature changes. This means fiberglass windows are have one of the lowest rates of seal failure of any window frame material, with nearly all cases being the result of improper installation. Additionally, fiberglass naturally resists ultraviolet rays, without the use of protective finishes. And, they’re less likely to warp than vinyl windows.
According to the U.S. Department of Energy, fiberglass windows offer better energy efficiency than both vinyl and wood. Their thermal performance is enhanced by the fact that they’re stable dimensionally, and they have air cavities that can be filled with insulation.
Neither vinyl nor fiberglass require much maintenance besides cleaning. Both types are made with colors that are already baked in, but if you want a change, fiberglass can be painted later while vinyl can’t.
Since it’s a stronger material, less fiberglass is needed for the window frame. That means you’ll get more glass space with a fiberglass window than with the same size vinyl frame. And, if you want the look of real wood, you’ll get more realistic results with fiberglass than vinyl.
Fiberglass window frames are “greener” than vinyl, because they are made with 60% glass which can be recycled.
Although fiberglass windows are affordable price, vinyl windows cost slightly less. This cost difference is made up for by the durability and longevity of fiberglass frames, as well as the fact that they’re more upscale than vinyl, so they can increases the resale value of your home.
Learn more about the features wood, vinyl, fiberglass and aluminum windows on our window frame materials page.