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Finding the Best Fiberglass Windows for Your Home


The best windows for your home means considering window material, durability, and budget. See why Marvin Replacement Ultrex® fiberglass windows are a great fit for your home.

Best Window Materials

Finding the best windows for your home starts with the material you choose. Common window materials include wood, vinyl, aluminum, or fiberglass. Each window material offers different performance and style features. At Marvin Replacement, we use Ultrex fiberglass

Ultrex® fiberglass

A pultruded composite material made of resin and glass fibers with an integrated proprietary finish.

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for our windows and doors because it outperforms other options.  

Fiberglass Replacement Windows 

  • Our Ultrex fiberglass provides 8x the strength of vinyl with virtually zero maintenance.  

  • Ultrex fiberglass also helps keep homes cooler in the summer and warmer in the winter. It’s 5,000x less conductive than aluminum.  

  • Our windows have five different interior color options, including EverWood®, our stainable finish that mimics the look of wood. We offer seven exterior window colors: Stone White, Sierra, Ebony, Pebble Gray, Cashmere, Bronze, and Bahama Brown.  

  • Our finishes last long—48,000 hours of sun can’t fade our finishes.*

    *Based on average sunlight exposure over 10 years 

Wood Windows 

  • Wood is a classic favorite for windows, but wood windows can require care and maintenance. 

  • Wood windows can get painted or stained in any color to suit a home and are energy efficient. 

Vinyl Windows 

  • Homeowners like vinyl windows because of their durability and versatility.  

  • Vinyl works well in most climates. But if exposed to direct sunlight and extreme temperatures, vinyl can expand. In extreme cold temperatures it can contract and become brittle.  

  • Vinyl windows offer an affordable window option and can come in colors to match your home. 

  • Repainting vinyl usually takes a special kind of paint. Paint doesn’t adhere well to vinyl due to its expansion and contraction.

Aluminum Windows 

  • Homeowners value aluminum windows because of their strength and durability.  

  • Since aluminum is a metal, it has high conductivity. That means hot and cold temperatures pass through it easier than other materials. Some manufacturers combine aluminum with wood for the energy efficiency properties of wood windows.  

What is a Fiberglass Window?

A fiberglass window gets constructed with strands of glass cables saturated with specifically compounded resins

Resin

Resin is a substance used with fiberglass to strengthen it. Ultrex fiberglass is saturated with specifically compounded resins until the two materials become one. It means it won't soften or melt when exposed to environmental temperatures.

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. Those strands get pulled through a heated die and cut with a diamond-edge blade to form Ultrex. Ultrex gets an acrylic finish applied to provide your windows their color.

Fiberglass Window Pros

  • Low-maintenance: Ultrex requires nearly zero maintenance.

  • Strength: Ultrex can protect the integrity of your home. Ultrex retains its shape better than vinyl for greater stability. Better stability means windows less likely to suffer from seal failure, leaks, and stress cracks.

  • Durability: Ultrex has a finish 3x thicker than competitive options. Plus, it's virtually fade-resistant.

Frequently Asked Questions

Are fiberglass windows better than vinyl?

Durability matters when comparing fiberglass vs. vinyl windows. Ultrex is tough enough to withstand wind, hail, branches, and even a direct hit from a baseball. It also handles extreme temperatures. Ultrex will not lose its shape even when exposed to temperatures of up to 285° F. Vinyl can start to soften at 163° F.

Are vinyl windows bad?

Vinyl windows offer an affordable option. But they come with fewer benefits when compared to Ultrex fiberglass windows.

Can you paint fiberglass windows?

Yes, you can paint fiberglass windows.

How do you clean fiberglass windows?

Our Ultrex fiberglass windows need virtually zero maintenance. You might want to inspect them annually to note any potential issues. Cleaning windows doesn’t involve a lot of work. A non-abrasive microfiber cloth and dish soap can do the trick.

Are fiberglass windows good in cold weather?

Fiberglass windows perform well in cold weather. They are some of the best windows for cold climates. Vinyl windows can become brittle in cold weather. Ultrex fiberglass expands 87% less than vinyl for superior stability.

Are fiberglass windows better than aluminum windows?

When comparing fiberglass windows vs. aluminum windows a few things stand out. Fiberglass windows have less conductivity than aluminum windows. That means it’s tougher for heat to pass through fiberglass than aluminum. Since aluminum is a metal, heat and cold passes through easily. That heat transfer can decrease your home’s energy efficiency.


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