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Fiberglass Windows vs Vinyl

When we need our windows replaced, where do we start? Choosing a material is a good place to begin. While windows come in several different frame materials, this is a comparison of two of the most popular frame materials, Vinyl and Fiberglass.


Vinyl windows are made of PVC plastic. This is an affordable material and can be produced for about half the price of some other window frames like wooden ones. They are also fairly energy efficient frames with a decent R-Value (the higher the R-Value the better the material is at insulating from outside temperatures). Another benefit to vinyl is that they can be made to fit any opening size. Vinyl is also durable and sunlight resistant so it will never need to be repainted, as there is no fading. They have a range of color options to choose form as well. Vinyl windows are readily available through nearly any window company including value dealers like Home Depot. So if Vinyl has all of these positive features, why would you consider Fiberglass?


Check out this video for an overview of Fiberglass.

Fiberglass starts with polyester that has been activated and then pulled through a heated die. Strands of glass are then pumped full of the polyester resins. Fiberglass can be shaped, is very strong, and also lightweight. So light in fact, that it's used in floating devices, surfboards, canoes and even skis. Fiberglass windows were introduced specifically to be better than vinyl frames. As Vinyl ages, it loses it's resiliency, unlike Fiberglass. Fiberglass windows also win in energy efficiency, while having smaller frame thickness which is often seen as more appealing. Fiberglass is much strong than Vinyl, and comes in more colors, and can also be easily painted, as it is not a porous surface like vinyl. Fiberglass can also be manufactured to resemble wood, and is scratch resistant. Fiberglass also expands and contract less than vinyl. Since glass is the main component in Fiberglass, it will actually expand and contract at the same rate as the glass window pane, allowing less room for leakage during temperature changes.

The Comparison

Both vinyl and fiberglass are cheaper than wood, but vinyl is even cheaper than fiberglass. Vinyl is up to 30% less expensive to purchase, and also comes with a generally cheaper install price. Fiberglass is harder to install because is call for more precision. It's also harder to fine someone to install a fiberglass window if they were not the seller of the window, so shopping somewhere like Home Depot, then trying to hire a certified installer isn't a good option for fiberglass. The warranty will most likely be voided if you try to take that route. Vinyl and Fiberglass both beet wood in terms of durability though, as bugs love to munch through organic materials like wood, leading to rotting and leakage. Fiberglass beats Vinyl though as it has about a 38% longer life span. Moving on to sustainability, fiberglass wins again. Fiberglass is made of around sixty percent recycled material, where PVC plastic is not, and is also very hard to recycle or reuse. Fiberglass windows also tent to have a higher R-Value than Vinyl. It can be up to a 15% difference, but you want to focus more on the actual panes and gas between them when considering your R-Value. many different parts of a window create the overall R-Value. Fiberglass frames in general though, do insulate against sound better than vinyl. Even though Fiberglass is more expensive to purchase and install, they reap a higher ROI, if you are ever planning to sell your home. For an end note, vinyl and fiberglass are both good option. Vinyl is cheaper, but you get what you pay for in appearance, durability, and insulation.

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