Advantages of Fibrex Material

The Strength of Wood. The Low Maintenance of Vinyl.

Exclusive to Renewal by Andersen®, Fibrex® material eliminates the worry of rotting, warping, and painting—redefining what a replacement window can be.

What is Fibrex® Material?

For decades, homeowners had to choose between two imperfect options: the beauty of wood (which rots and requires painting) or the convenience of vinyl (which is often structurally weak and prone to warping).

Renewal by Andersen refused to settle. After 30 years of research and development, they perfected Fibrex® —a revolutionary composite material.

The Composition:

Fibrex is created by fusing 40% reclaimed wood fiber with 60% proprietary thermoplastic polymer.

This unique molecular bond creates a material that retains the structural integrity and insulating properties of wood, while offering the fade- and maintenance-free durability of high-grade vinyl.

How Fibrex® Stacks Up Against the Competition

Why do we use Fibrex® material for every window we install?

Because it solves the problems that cause other materials to fail.

Feature Fibrex® Material Vinyl Wood Aluminum Fiberglass
Strength Prone to bowing Strong, but degrades Strong Strong
Maintenance Low High (Painting/Sealing) Low Low
Insulation Good Good Poor (Conducts Cold) Good
Rot/Decay Never Yes, over time Never Never
Aesthetics Plastic Look Upscale Commercial Look Painted Look

Vs. Vinyl: Fibrex is twice as strong as vinyl, meaning your frames won’t bow or sag over time, keeping your seals airtight.

Vs. Aluminum: Fibrex blocks thermal transfer nearly 700 times better than aluminum, keeping your home warmer in winter and cooler in summer.

Vs. Wood: Unlike wood, Fibrex is warranted not to rot, decay, or mold.

Engineered for Wisconsin Winters

In Wisconsin, our windows face extreme temperature swings—from sub-zero freezes in January to humid highs in July.

Most materials expand and contract significantly during these changes, leading to broken seals and drafts.

The Stability Factor:

Fibrex® has an extremely low thermal expansion rate. It expands and contracts very little, much like the glass it holds.

The Result: The seal between the frame and the glass remains tight for the life of the window.

The Benefit: No icy drafts, no fogged-up glass, and lower heating bills for you.

Durability That Doesn’t Sacrifice Beauty

Stronger materials mean we can use less of them. Because Fibrex is so rigid, our sash and frames can be narrower than those of bulky vinyl windows.

This gives you more glass area and a better view of the outdoors.

Dark Colors Without the Risk:

Standard vinyl windows often cannot withstand dark colors because they absorb heat, which can cause the plastic to warp and distort.

Fibrex® is thermally stable, allowing us to offer deep, rich colors like Black, Dark Bronze, and Forest Green that stay true and won’t warp in the sun.

Custom Shapes: Our unique extrusion process allows us to craft curves, arches, and specialty shapes that other replacement windows simply can’t match.

A Responsible Choice for Your Home & Planet

Fibrex® isn’t just smart for your home; it’s smart for the environment.

Reclaimed Materials: The wood fibers used in Fibrex are reclaimed from Andersen’s manufacturing operations—preventing the harvesting of new trees.

Clean Air: Our windows meet the strictest indoor air emission standards in the U.S.

Energy Efficiency: By blocking thermal transfer and maintaining tight seals, Fibrex reduces the energy load on your HVAC system, lowering your carbon footprint.

Protected by the Nation’s Best Warranty

We believe in our product so much that we back it with one of the strongest warranties in the industry.

  • 10-Year Coverage on Fibrex® Material: Warranted not to rot, chip, corrode, flake, blister, or peel.
  • 20-Year Coverage on Glass: Covering defects in material and workmanship.
  • Fully Transferable: If you sell your home, the warranty transfers to the new owner—increasing your home’s resale value.
FeatureFibrex® MaterialVinylWoodAluminumFiberglass
Strength2x Stronger than VinylProne to bowingStrong, but degradesStrongStrong
MaintenanceVirtually Maintenance FreeLowHigh (Painting/Sealing)LowLow
InsulationSuperiorGoodGoodPoor (Conducts Cold)Good
Rot/DecayNeverNeverYes, over timeNeverNever
AestheticsUpscale Look of WoodPlastic LookUpscaleCommercial LookPainted Look