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Posted on Oct 01, 2019 by Sam Heer

Why Wood and Vinyl Windows Warp

Warping is a common problem in wood and vinyl windows, resulting in deformity that not only looks unsightly but also prevents a window from properly working and functioning. It can come in many forms, including bowing (bending along the window face), crooking (bending along the window edge) and cupping (inward or outward warping that creates a cup-like bend).

What Causes Warping

Wood and vinyl windows warp for different reasons. In the case of wood windows, warping occurs when wooden frames absorb and retain moisture. This results in deterioration that prevents a window from keeping its form. Constantly being exposed to temperature changes also causes frequent expansion and contraction that eventually give rise to bending.

As for vinyl windows, warping is the result of heat exposure. Heat softens vinyl as it warms it up, making window frames more malleable. Locking vinyl windows strains framing material, making it bend inward. When vinyl cools, it hardens, retaining the frame’s warped form. 

What You Can Do About It

There’s no avoiding exposure to heat and moisture so the next best thing for you to do is to look for replacement windows that can withstand it. This is precisely what Fibrex® windows can do. 

Made of a mix of thermoplastic polymer and reclaimed wood fibers, Fibrex is a composite framing material that brings together the best attributes of wood and vinyl windows: It certainly won’t warp, retaining its shape even with constant moisture exposure and temperature changes, all while offering beauty, maintenance ease and energy efficiency. 

Renewal by Andersen® of Central Illinois is your leading choice for quality window installation services and Fibrex products for your home. To learn more about what we can do for you, simply give us a call at (866) 693-6707 or fill out our contact form. Schedule a FREE consultation with us today! We serve Peoria, Champaign and the surrounding IL communities.


"I would recommend RBA of Central Illinois for QUALITY windows and doors. Compared to our old cheap, thin vinyl windows, Andersen blows them away. You can easily tell by how well the sliding doors fit and close, and how heavy duty they are. We also cannot hear the wind rushing through the house in inclement weather anymore! And the black window frames we went with are amazing to look at. Aaron, Al, Darrell, and Cory all were professional and went all out to finish the job, given the weather they had to deal with. I would definitely recommend. They were also on top of communicating with me given the weather delays, and what I could expect for them coming out. Five stars!"

Eric L.

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