Traditional wood style, fiberglass strength and durability.

Exceptionally strong and low-maintenance fiberglass patio door frames from Milgard are ideal for any style and climate.

Milgard windows and doors Denver
Milgard Fiberglass Patio Doors and Windows Denver

When you first look at Milgard® fiberglass patio doors, you might think you’re looking at an all-wood door.

Fiberglass frames are essentially composed of glass fibers and resin, materials that expand and contract very little with temperature changes in the weather. Until recently, the complex profiles required for window and patio door designs have been impossible to attain with fiberglass. Innovation has made it possible to design a fiberglass frame and fiberglass windows and patio doors are becoming more popular among homeowners for its beauty and long-lasting durability.

Fiberglass windows and doors resist swelling, rotting and warping. The frame expands and contracts at approximately the same rate as the insulated glass it holds for improved energy efficiency and strength. While fiberglass frames do not require repainting for upkeep, the material is able to be repainted if you prefer to change colors.

Milgard’s fiberglass is produced using a process called pultrusion. Glass rovings and mats are pulled at tremendous forces through a resin bath and a series of dies. These materials combine and catalyze to provide tensile and torsion strength. Every Milgard fiberglass frame is tested for color uniformity, gloss, film thickness and chemical resistance for quality and long-lasting performance.

Built to last and accent your home with a beautiful, contemporary style.

Create a grand entrance with Ultra Series fiberglass, French-style patio doors. These French doors are a simple addition that can add intricate detail to your space. Ultra Series fiberglass patio doors are strong. Because of its inherent properties, fiberglass is resistant to swelling, cracking, warping, peeling, splitting, corrosion and is virtually impervious to water. Choose from their energy efficient options to meet or exceed ENERGY STAR® requirements. Ultra Series patio doors come with the Milgard Full Lifetime Warranty, including Glass Breakage Coverage.

Available in these styles:

Sliding French Patio Door Inswing French Patio Door Outswing French Patio Door

Beautiful, natural wood interior finish with strong fiberglass exterior.

Highly regarded as the finest patio door Milgard manufactures, the Essence Series is a patio door like no other. Featuring a durable fiberglass exterior and a natural wood interior, the frame has been engineered to have no visible fasteners for lasting beauty and exceptional performance. The fiberglass exterior is low-maintenance and offers long-lasting performance that will not crack, peel, bend, warp or stick due to expansion and contraction. It is also resistant to cold, heat, water, insects, salt air and ultraviolet rays.

Enjoy superior energy performance with our SunCoat® Low-e glass coating that comes standard. Essence Series patio doors are covered by the Milgard Full Lifetime Warranty. 

Available in these styles:

Sliding French Patio Door Inswing French Patio Door Outswing French Patio Door

Fiberglass Window and Patio Door Tips

Quality Milgard brand fiberglass windows and patio doors have lots going for them: Lifetime parts and labor warranty, EnergyStar rating, low E glass and custom sizes at economical costs. So why consider upgrading to fiberglass?

The “Ultra” is all fiberglass. The “Essence” is the same, with an unfinished fir veneer on the interior.  More expensive than vinyl, they have the same qualities listed above. Should you spend more and upgrade to fiberglass?

Milgard’s peerless warranty for the original purchaser of the window (with 10-year transferability from date of manufacture) and the perceived longer life of a fiberglass product make them a more popular choice all the time.  Fiberglass’s reputation for strength, paintability, imperviousness to UV rays and chemicals and overall durability should add extra value to a home for years longer than vinyl and wood windows can.

Here is a review of important qualities of fiberglass:

Paintability: While five EXTERIOR factory finishes are standard, many choose white to leave as is or to paint. Painting is as easy as on wood, but you should expect a longer life. Wood can soak up water and humidity, leading to peeling. By getting fiberglass, you are leaving yourself and future building owners open to any color wished. Painting does not affect warranty unlike most brands “clad” products that are voided if painted. You can even paint Milgard’s black!

The “Ultra” INTERIOR is paintable white. The Essence woodclad interior is a vertical grain Douglas fir – it can be stained and finished. As you open this window or patio door you will see that the edges of the sash are not covered by veneer. This makes finishing much easier than wood windows and patio doors. To adequately finish them you would have to disassemble all hardware to get to all the nooks and slots where water drips and spiders hide.

Strength: Vinyl doors can only slide. Fiberglass is strong enough to swing also, giving you all options for exterior doors. Poor quality or dark colors can make vinyl products warp or bow; this cannot happen with fiberglass due to its extremely low thermal expansion and contraction rate. Vinyl windows are joined at corners by heat, melting the pieces together. Fiberglass corners are joined with gaskets, sealants and a mechanical attachment with screws.

Warranty: Most windows and patio doors in the price range of an “Ultra/Essence” have a 20-year glass, and 10-year non-glass warranty. Please read Milgard’s warranty. It clearly exceeds these limits.

Some brands require installation by a factory representative. This traps you and can really increase the total cost. As long as they are properly installed, any contractor or homeowner can install Milgard windows and patio doors and have a full warranty!

Energystar: The federal government has established criteria for a recommended minimum level of energy saving qualities in windows and patio doors. These criteria are not required but are met in the fiberglass line. Low-E Max glass and a “super-spacer” ensure this desirable designation.

We, as a small family-owned business have partnered with Milgard. They take care of us and our customers.

By installing yourself, or arranging a separate contractor, you can get great windows at the lowest price!

Essence Woodclad Staining Tips

Milgard’s woodclad Essence series of doors and windows is a durable, beautiful alternative to a regular pine/clad product.  An architectural grade veneer is applied to the inside of the face and jamb. The veneer, Douglas fir, has been used for quality doors and mouldings for over 100 years in the U.S.A.

Douglas fir, like cherry and some other woods, darkens naturally with even indirect sun light. You will have a medium color finish even without stain. Woodclad products can be stained if you wish. As can happen with any veneered product, stain can “bounce” off the substrate, causing uneven staining. Always test a small area before going to far.

Generally, we recommend oil based U-V protective polyurethanes on the inside of woodclads. These would be the longest lasting finish. Use 2 to 3 coats. Oil-based finishes will bring out more color, especially the “Salmon” color in the fir.  If a more tan color is desired, water-based finishes will mute the reds in the fir.

Please note: All product items/sizes/lengths/brands may not be available at either location, please call to verify availability.


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