cross section of pella fiberglass window material with callouts

Pella Fiberglass vs. Marvin Fiberglass

    Intentional vs. Random, Which Strength Would You Prefer?

    Your project deserves the best fiberglass window and door material. To see how we stack up against the competition, we put our exclusive fiberglass, developed using our one-of-a-kind manufacturing process for superior strength, and Marvin, basic randomly blown fiberglass, to the test.

    Won't Bend
    On average, Pella fiberglass is
    1.4x

    stronger than Marvin fiberglass in a bend test.36

    Won't Break
    On average, Pella fiberglass has
    2.2x

    the tensile strength of Marvin fiberglass.37

    Pella Outperforms Marvin with Unmatched Strength and Lasting Durability

    Pella's proprietary fiberglass material is the strongest material for windows and patio doors, engineered for lasting durability.9

    As much as the competition in a bend test, which measures the flexural strength of a material by applying force via a single, concentrated load point in the middle.
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    3-point bend testing performance based on testing 7 samples of each material using ASTM D790 test methodology.

    The Strongest Fiberglass vs. Basic Fiberglass

    Take a look behind the paint and see what materials make up Pella’s proprietary fiberglass and Marvin basic fiberglass.

    a close view of pella's fiberglass material

    Pella Impervia, made of our proprietary fiberglass

    To meet Pella’s exceptionally high strength standards, our fiberglass starts with a proprietary structural mat. These strategically woven rovings and additional rovings are pultruded, or pulled through a machine, and heated with a polymer resin to create a thermoset material that won’t break down. Our fiberglass is the strongest material available for windows and patio doors.9

    a close view of traditional fiberglass material

    Marvin Ultrex, a basic fiberglass

    Marvin’s Essential Collection windows and doors use randomly blown fiberglass rovings and heated with resin until the materials become one. The randomness of the fibers means it cannot withstand the incredible strength Pella Impervia fiberglass can.

    Find the Right Product For Your Project

    Work with a dedicated Pella representative every step of the way.

    I'm a ProI'm a Homeowner
    pella rep helping a window customer
    Bringing Our Superior Strength to Life

    01:34

    Withstanding a 10-pound bowling ball drop
    See How Our Fiberglass is the Best Fiberglass for Your Project
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    A child plays with toys by a large black fiberglass window in a bright, modern room.
    Get the Best Fiberglass Windows & Patio Doors

    Designed to stand up to everyday wear and tear, Pella Impervia products offer an on-trend color palette, including black, and feature our latest innovation, the Easy Slide Operator window hardware, winner of Best in Show at the 2021 International Builders Show.

    Explore Additional Product Details

    Ready to take the next step?

    Work with a dedicated Pella representative every step of the way.

    I'm a ProI'm a Homeowner