Building a better window with Ultrex pultruded fiberglass.
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The History of Ultrex®

For nearly a century, Marvin Windows and Doors has cultivated a worldwide reputation as an industry leader in product innovation, energy efficiency and progressive manufacturing techniques. Bringing you superior windows and doors through exceptional design, the highest quality materials and an extraordinary level of service.

With almost two decades of experience in the development and manufacturing of Ultrex, Marvin has established itself as the industry leader in fiberglass pultrusion. The superior performance of Ultrex is the result of patented processes that provide exceptional durability and stability, with attractive, detailed product designs not found in alternative composite materials including other pultruded fiberglass.

Today, Ultrex is available in a wide range of beautiful, long-lasting windows and doors.

Ultrex Timeline

Marvin pioneered Ultrex pultruded fiberglass, offering the design detail, strength and durability required for long-lasting, beautiful windows and doors.

Marvin Windows and Doors:


Marvin introduces Ultrex sills on Sliding French Doors, Replacing inefficient aluminum sills found on most doors.


Marvin introduces Ultrex sills on Inswing and Outswing French Patio Doors.

Integrity Windows and Doors:


Marvin introduces Integrity Windows, a new product line made exclusively with Ultrex pultruded fiberglass.


Integrity Windows and Doors begins manufacturing in Fargo, North Dakota.


Integrity opens a second manufacturing plant in Fargo, North Dakota and launches its new Wood-Ultrex series.


Integrity introduces Sliding Patio Doors. Its first patio door made of Ultrex pultruded fiberglass.


Integrity introduces Inswing French Doors. The first hinged patio door with frames, door panels and sills made of Ultrex pultruded fiberglass.


Integrity opens an Ultrex pultruded fiberglass manufacturing facility in Roanoke, Virginia.


Integrity introduces its All Ultrex series of windows and doors.


Integrity introduces IMPACT windows featuring an extra-strong Ultrex fiberglass exterior that is built to withstand hurricane-force wind.

Infinity Windows and Doors:


Marvin introduces Infinity Replacement Windows, releasing its first product, the insert double hung.


Infinity Replacement Windows opens a new manufacturing facility in West Fargo, North Dakota.