Aluminum vs Fiberglass Patio Doors

Aluminum vs Fiberglass Patio Doors

When shopping for new or replacement patio doors, you’ll find that you have tons of options. Modern doors and windows are available in a variety of materials each of which has its pros and cons. 

In this post we’re comparing aluminum vs fiberglass patio doors, you’ll learn the differences and similarities between each material and find a few brand options at the end. 

Aluminum Patio Doors

Benefits of aluminum

  • Strong
  • Durable
  • Weather-resistant (won’t warp, rot, or corrode)
  • Insect-resistant
  • Inexpensive
  • Low-maintenance

Drawbacks of aluminum

Aluminum is one of the most common materials used for making windows and patio doors. Its strength and durability make it a good building material. The inherent strength of aluminum(↗) allows manufacturers to design doors with narrow frame widths and larger glass units delivering the contemporary look homeowners, builders, and architects are looking for. Additionally, aluminum patio doors are available in beautiful finishes and are low-maintenance. 

Unfortunately, aluminum isn’t perfect. Because of the lightness of the material, it can be dented and scratched. Scratches to the finish of aluminum products breakdown the protective layer on the metal making it susceptible to corrosion. Aluminum also isn’t an energy-efficient framing material, it requires thermal breaks (structural insulating material) between the interior and exterior sides of the frame to decrease thermal conduction(↗). Thermal breaks and a well-insulated glass unit are necessary for energy efficiency. 

Despite some of its drawbacks aluminum is still a popular material for exterior building products including used as cladding(↗)

Learn more: What are insulated glass windows?

Fiberglass Patio Doors

Benefits of fiberglass

  • Strong
  • Durable
  • Lightweight
  • Energy-efficient
  • Glass and frame expand and contract at the same rate
  • Weather-resistant (won’t warp, rot, or corrode)
  • Insect-resistant
  • Low-maintenance

Drawbacks of fiberglass

  • Relatively expensive material

Fiberglass is a composite that has been around since the 1930s(↗). Only as recently as the early 2000s(↗) has fiberglass gained popularity in windows and doors. According to Milgard(↗), fiberglass windows and doors were designed to address “the demand for a strong, durable, and low-maintenance frame type that would be sustainable and environmentally friendly.” Fiberglass products have a low carbon footprint, are energy-efficient, and are built to last.

Although fiberglass doors are one of the more expensive options on the market, they are low-maintenance and extremely durable. Like aluminum, fiberglass is resistant to warping and corrosion and rot isn’t a concern. Fiberglass doors are stronger and more resistant to dents and scratches and offer better energy performance overall. 

Learn more: Pros and cons of each window material


Most patio doors have a full or half-panel of glass. Glass is beautiful but as a poor insulator it’s important to choose a glass package that helps your aluminum or fiberglass patio door meet ENERGY STAR(↗) criteria. 

Close-up of a thermal break in thermally improved aluminum.

To make glass energy-efficient manufacturers use glass units with multiple layers of glass, low-emissivity coatings, and/or low-conductivity glasses(↗).


Aluminum and fiberglass patio doors are both low-maintenance. Since patio doors come in contact with outside debris, it’s important to clean them to protect the exterior finish. Regularly cleaning doors with a mild soap can help keep your doors in good condition. For aluminum doors, regular cleaning is especially important because it provides an opportunity to look for scratches.

Scratches on aluminum doors and windows leave the metal vulnerable to corrosion. If you choose an aluminum product check the warranty to see what kind of coverage is provided.


The color and finishes available for patio doors will vary depending on the manufacturer. Typically, aluminum products offer more color options. In fact, Andersen offers over 50 powder-coated colors and 7 anodized finishes for its aluminum-clad patio doors while only offering 11 colors for its fiberglass-clad patio doors. 

Andersen Aluminum Colors

Sample color swatches for Andersen aluminum exteriors.

Andersen Fiberglass Colors

Color swatch examples of colors available on Andersen fiberglass windows and doors.


When aluminum has a powder-coated finish it’s nearly indistinguishable from fiberglass. Both are versatile materials that can be made into thin profiles for a contemporary look and they can also be molded to simulate wood grains or be left smooth. What sets aluminum apart is its anodized finish options. Anodized finishes allow the look of metal to shine through, unlike powder-coated finishes which color over the metal. 



Black Milgard Ultra fiberglass hinged patio doors on house with white siding.

Milgard has been in business for over 50 years, through their vertical integration Milgard is able to control the quality of their products from start to finish.

Aluminum Patio Doors
Thermal Break Aluminum

Fiberglass Patio Doors
Fiberglass-Clad Essence Series®
Ultra™ Series



Aluminum exterior patio doors with light green finish from Andersen.

Andersen is consistently rated as the most trusted and recommended brand of windows and doors among homeowners. They offer sliding and hinged patio door options.

Aluminum Patio Doors
E-Series Gliding Patio Door
E-Series Hinged Patio Door

Fiberglass Patio Doors
A-Series Gliding Patio Door
A-Series Hinged Patio Door



 Three-panel hinged patio door system from JELD-WEN.

JELD-WEN was founded in 1960, they’ve quickly grown into one of the world’s largest door and window manufacturers. 

Aluminum Patio Doors
Premium Atlantic Aluminum Sliding Patio Door(↗)
5 Aluminum-Clad Patio Doors(↗)

Fiberglass Patio Doors
IWP® Aurora® Fiberglass Patio Door(↗)
16 IWP® Aurora® Fiberglass(↗)


Two-panel white sliding patio doors from Pella.

Pella began offering sliding glass doors over 50 years ago and today they offer several aluminum and fiberglass patio door options. 

Aluminum Patio Doors
Aluminum-Clad Pella Lifestyle Series(↗)
Aluminum-Clad Architect Series Traditional(↗)
Aluminum-Clad Architect Series Contemporary(↗)

Fiberglass Patio Doors
Fiberglass Sliding Patio Door Pella Impervia(↗)

We always recommend choosing a product that best meets your needs and offers the most value. Aluminum is great but may not be the best choice in areas with extreme changes in weather. Fiberglass is more expensive but it’s also the most durable and energy-efficient.

To learn more explore the links above or check out our related articles below.


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