Product Design Options

Fiberglass Windows and Doors

House with white siding and stamped concrete featuring a fiberglass elevate bi-fold door

Benefits of Fiberglass

Endures harsh weather conditions and climates with minimal wear and tear over time
Virtually maintenance free
Provides exceptional structural strength, ensuring windows and doors open and close easily for years to come
Does not expand and contract with dramatic changes in temperature, making the product resistant to leaks, seal failures, and stress cracks
When combined with energy-efficient glass options, fiberglass keeps the indoors comfortable regardless of what’s happening outdoors

Fiberglass Window and Door Product Lines

Elevate

Features our proprietary Ultrex fiberglass exterior paired with warm pine wood interiors.

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Essential

Both the interior and exterior feature low maintenance and durable Ultrex fiberglass.

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Modern

Modern windows and doors are built with a high-density fiberglass exterior and a low-gloss aluminum interior.

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Why Choose Marvin Fiberglass Windows and Doors

Not all composite materials are created equal. The fiberglass used in Marvin windows and doors is made with lineal fiberglass and thermoset plastics. This is what sets Marvin fiberglass apart from composites made with sawdust, vinyl, and other low-cost materials.

Highest Quality Inputs

The high percentage of lineal fiberglass in Essential, Elevate, and Modern products contributes to the long-term performance. Because of the high concentration of glass, Marvin fiberglass expands and contracts very little regardless of the changing temperatures. This stability means fiberglass windows and doors are less likely to experience seal failures, leaks, and stress cracks.

Strength

Ultrex fiberglass is 8x stronger than vinyl and 3x stronger than vinyl/wood composites. Fiberglass is incredibly rigid, which makes it highly impact resistant and capable of standing up to everyday wear and tear, especially in extreme weather conditions.

Fiberglass frames and sashes are less likely to bend and twist helping protect the structural integrity of your home.

Category-Leading Performance

Because of their strength, fiberglass frames and sash are typically narrower than other types of frames but are still able to meet the structural performance requirements. More streamlined frames and sashes create an uncluttered aesthetic with less frame, more glass, and bigger views.

Superior Process

Ultrex and Marvin high-density fiberglass are created through a process called pultrusion. The pulling versus pushing action of pultrusion makes it possible for long, lineal glass fibers to become embedded and highly concentrated in the fiberglass as it is pulled through a dye. This high concentration of glass fibers results in superior strength and an exceptionally smooth and durable finish.

A Finish That Lasts

Marvin fiberglass offers a premium, smooth finish – unlike rough textured finishes on some competitive composite products.

Ultrex features an acrylic finish* that is bonded to the fiberglass through a proprietary process. The Ultrex finish protects against fading, chalking, and gloss retention.

The Marvin high-density fiberglass finish** is baked on at extremely high temperatures resulting in a finish that exceeds a high-quality aluminum car paint.


*AAMA 624 verified
**Undergoing AAMA 625 verification

Fiberglass Window and Door FAQs

A strong, durable, fiberglass proprietary to Marvin. Used for the exteriors of Elevate products and the interiors and exteriors of Essential products.

The finish is AAMA 624 verified which means it has undergone rigorous tests that simulate the difficult conditions a finish can encounter throughout the life of a window or door.

  • A fiberglass that shares many of the same characteristics of Ultrex but is even stronger

  • Used for the exteriors of Modern products

  • Mimics the clean look, feel, and strength of aluminum and steel with better insulating qualities

  • The high-density fiberglass finish is currently undergoing the AAMA 625 verification process.

Ultrex and Marvin high-density fiberglass are fundamentally different materials than vinyl with entirely unique properties. Fiberglass is a much stronger material than vinyl due to the base materials that make up fiberglass as well as the process by which fiberglass is created. Fiberglass is significantly more resistant to expansion and contraction, dents or cracks, making it a far more resilient material for windows and doors. In short, it’s able to stand up to daily wear and tear better.

Vinyl has a hard time standing up to extreme temperatures, which can weaken the integrity of a window or door, making it more susceptible to water leaks, poor window seals, and overall loss of shape and energy efficiency.

Fiberglass is a superior material for building strong, durable windows and doors. Fiberglass is also more fade-resistant and able to handle high temperatures, which is why it is available in darker colors. Contact your dealer to learn more.

Additional Resources

Trust Marvin Ultrex For Unmatched Performance

Explore the strength, durability, and proven performance of Ultrex Fiberglass.

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What Exactly is a Thermoset Fiberglass Composite?

You have a lot of choices when it comes to new construction and replacement windows and doors. Some composites are often less expensive, but it’s not always about the immediate cost.

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Warranty Information

Marvin products are covered by a Limited Lifetime Warranty providing peace of mind that Marvin products will last the entire time you live in your home.

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An entryway with Marvin Essential casement and awning windowsl

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