Fibrex™ vs Vinyl | Compare These Window Frame Materials

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Fibrex™ vs Vinyl | Let's Compare And Contrast

Fibrex™ vs Vinyl

Fibrex™ vs Vinyl how do they stack up against one another? Let's compare and contrast these two (not so) different window materials.

Dane - Site Editor - Page Updated In December, 2023

Please note, our website is not affiliated with any company that makes these materials.

"Fibrex™ is by far the better overall looking material in this match up, but Fibrex™ can't touch vinyl in terms of its thermal conductivity - which means that well made vinyl windows will be more energy efficient."

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Fibrex™ vs Vinyl | How Do They Match Up?

What Is Fibrex?

Fibrex™ is a composite material, which simply means that it is comprised of more than one material. The term, fibrex, is owned by the Andersen Corporation and used in their 100 composite series window, as well as in the windows sold by Renewal By Andersen. Fibrex™ is comprised of vinyl and wood particles (the percentage mix is roughly 60% vinyl and 40% wood particles (some say sawdust), although it is proprietary so the exact amounts and makeup is intentionally not perfectly known).

"According to the Andersen Corporation, Fibrex™ is TWICE as strong as pure vinyl. While this may be so, there are all sorts of ways that vinyl manufacturers can strengthen their products as well - which muddles the statement that Fibrex™ is 2x that of vinyl."

Andersen claims that their Fibrex™ window frame is considerably strong than vinyl (They claim it is twice as strong - whether or not this is true, I can’t really say, but perhaps it is when compared to very traditional PVC or vinyl. Keep reading to see why this isn't as important as it sounds when you initially here it.
( Andersen Windows Reviews )

What Is Vinyl?

Vinyl windows are made of PVC or polyvinyl chloride, which is a mixture of chlorine and ethylene. Essentially it is a synthetic plastic that is durable, mold resistant, and strong. Early iterations of PVC for windows had some significant issues such as bowing over time or losing shape (melting) in extreme temperatures.

Over time, manufacturers have worked to make the process better and their products stronger. One such evolution was the jump from from PVC to uPVC. UPVC does not contain any plasticisers, which makes the vinyl less malleable or flexible. The result is a more suitable window frame material that can better stand up to extreme temperatures.

Other developments include infusing materials into the uPVC to make the window frames stronger during the manufacturing process. This is more or less identical to a composite material, although it is often simply referred to as engineered vinyl. (In essence, Fibrex™ IS an engineered vinyl because it is a combination of two materials, one of them being vinyl.) Because the name is proprietary (and because Renewal is so popular), most consumers know it simply as Fibrex™.

Other proprietary names include Glastra™ by Kolbe and Ultrex™ by Marvin. ( Kolbe Windows Reviews )

An example of an engineered vinyl involves Anlin Windows, which includes titanium dioxide in their vinyl frame for increased strength. Other companies choose to strengthen their vinyl window frames by including more chambers, which adds to the over strength. Still others include reinforcements within the chambers for added strength and insulation.

The Bottom Line For Consumers

There are lots of approaches and subtleties that come up in the discussion of Fibrex™ vs vinyl. As a consumer or homeowner doing research on what material is best, all of this information can throw you down a rabbit hole. That’s why the bottom line for me is this: does the manufacture make a quality product that is strong and holds up over time? This should be the integral question. We look at brands and series year after year and with 100s of reviews and feedback from real homeowners in order to determine what brands make quality products. Ask us for our list -

Here is an example of how opinions here at RWR change over time. In 2021, Sunrise Windows And Doors was purchased by MI. To be blunt, MI does/did not have the best reputation for making quality windows - they have concentrated on builder grade windows that are more toward the bottom of the quality spectrum. We watched how they handled their acquisition of Sunrise. When we knew they left the production process alone, and changed the names of the windows, we are now endorsing the MI V Series (which is the generic name for the Sunrise seres). Changing with the times!

Want to know more of my favorite window series? Shoot me a quick email and I’m happy to share with you my faves.

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