Although fiberglass windows and doors may not be as widely known as those made of PVC, Aluminum or wood, they offer a wide range of advantages that make them very competitive and highly thought after in certain markets.

In this article, we will discuss the advantages and disadvantages of fiberglass windows and the applications they are most suited for. By the end of this article, you’ll have a robust understanding of fiberglass windows, and will be prepared to make an informed choice.

What are fiberglass windows?

Fiberglass windows are, as their name suggests, made essentially of fibers of glass held together by resin. It is the same material used for building boats, car body panels, and many other products that require strength and durability.

Fiberglass is a fairly new material for windows and doors because, until recently, it was very difficult to tailor fiberglass to the precise measurements of a window.

However, given modern technological advancements, precision has improved, and fiberglass can now be pulled together through molds while being saturated in resin to form parts called Profiles which are eventually cut to size to make Windows and Doors.

This process is called “Pultrusion,” and it is the opposite of the “Extrusion” process used to make PVC and Aluminum Window and Door profiles.

What are the pros of installing fiberglass windows?

There are several reasons why fiberglass should be your material of choice for windows and doors.

1) They’re incredibly resistant to thermal expansion:

While materials like PVC or wood are both really good options, they suffer from high thermal expansion, meaning the material will expand/contract in extreme weather. Fiberglass, however, will not.

Fiberglass enjoys extremely low thermal expansion and shows little to no reaction, even when faced with extreme heat/cold.

Not only that, but because the frame itself is made of the same type of glass as the window when fiberglass does expand or contract in harsh weather, it will all do so at once.

With other windows, the different materials between the opening and window would cause leaks of air, as they don’t expand at the same rate. But with fiberglass, you don’t need to worry about that.

2) They are extremely Strong:

Fiberglass is the preferred material for windows in high-risk hurricane areas like Florida or Louisiana. That’s due to the extreme resistance of fiberglass, which is estimated to be about seven or eight times stronger than PVC windows.

The resin in the fiberglass mixture holds the window together, and even should the window crack (from extreme weather), the resin acts as a type of glue, preventing window shards from flying everywhere.

3) Fiberglass windows are lightweight:

A common misconception is that being so resistant, fiberglass must also be really heavy. This could cause some concern for builders. But the good news is that fiberglass is one of the lighter materials you can choose for your windows.

While fiberglass is more resistant than materials like PVC or wood, it’s about the same weight, making it a big favorite in home construction, boats, and planes, where weight to strength ratio is very important.

4) Fiberglass windows are energy-efficient (and will save you money):

One thing that all homeowners want from their windows is good energy-efficiency, which also translates to low thermal conductivity. You want windows that, once closed, will not allow the heat within to leave the house.

That’s one thing you can look forward to with fiberglass. It has extremely low thermal conductivity, meaning you won’t need to worry about losing the heat you worked so hard to create inside the house during cold months.

In addition, low thermal conductivity works to your advantage in the summer, as well, since the effect is reversed. By closing the fiberglass windows, you’re effectively creating a shield between the cool interior of your house and the high temperatures outside.

5) They have strong weather resistance:

You want windows that can face any weather, and once again, few materials can compare to the resistance of fiberglass.

Not only does it not expand or contract in extreme temperatures, but fiberglass also demonstrates resistance to water, Sunlight, Heat, Snow, Ice, Salt Water, and Acidity.

Fiberglass will resist all of these conditions, and while the color may fade after a few decades of Sun Exposure, it will not rot or develop mildew, mold, or pit due to acidity and exposure to salt.

Fiberglass won’t do any of those things. Nor do you need to worry about your windows rusting or warping in time.

6) You can Paint and Repair fiberglass Windows and Doors:

Fiberglass can be painted in any color or laminated with Stainable Wood foils. This makes Fiberglass hugely versatile. It helps fiberglass compete even in applications that call for wood windows without the durability and high maintenance issues associated with wood.

Maintenance-wise, Fiberglass can be sanded, painted, and repaired as you would Wood Windows. Fiberglass can also be repaired using commonly found materials and techniques similar to those used to repair Boats and automobile body panels.

7) They are eco-friendly:

We live in a time when it’s not longer enough to worry about what works best for us but about how our actions impact the world around us. Fiberglass windows are considered an eco-friendly choice since they are largely made of sand.

Sand is an easily available and plentiful resource that can swiftly be recycled. Also, the manufacturing of fiberglass windows is less energy-consuming than other windows, making these a great choice for the environment.

8) They’re the closest you get to soundproof:

Particularly if you live in a busy neighborhood, it’s not outrageous to crave some peace and quiet from time to time. Because fiberglass is such a strong material, it allows for almost no leaks once the window is closed. This allows you to maintain the temperature inside the home and minimize external sounds.

While no window is 100% soundproof on its own, fiberglass is probably the closest you can get, short of actually soundproofing the house.

9) Fiberglass is low-maintenance:

Unlike other window materials, fiberglass doesn’t require regular re-coating and is very easy to clean and look after. However, remember that you’ll need to have your fiberglass windows powder-coated to increase UV resistance (else they’ll fade in time).

10) Fiberglass windows will increase home value:

Since fiberglass is one of the strongest materials available, fiberglass windows can greatly increase the resale value of your home should you decide to sell. Even if you live in a non-risk area, fiberglass windows are a great comfort, as they improve family safety and save you on energy bills.

Are there any downsides to fiberglass windows?

While we can’t stop talking about how great fiberglass is, there are also a couple of cons we need to mention.

1) Fiberglass is more expensive:

Fiberglass windows tend to be up to 30% more expensive than other window materials. On top of that, it’s a rarer type of window, meaning you might need to search for it a bit.

2) You need a professional to install it:

While you may install other windows on your own, thus saving some money, fiberglass windows need to be installed by a professional.

3) They cannot be Bent or used to make Arched Windows & Doors:

Fiberglass windows offer a lot of customization options. However, fiberglass is not Flexible and, unlike Aluminum, Wood, and PVC, cannot be bent to make Arched or Elliptical Windows or Doors.

Most Manufacturers will substitute the Arched part of a Fiberglass window with PVC. Others will build Segmemented Arches using Fiberglass.

Segmented Arches are arches formed by joining many small pieces of Fiberglass profiles, cut at a calculated angle, so that when put together, the form and Arch. While this technique is expensive, it is very aesthetically appealing.

Are fiberglass windows worth the extra cost?

Yes. While they may be more expensive, fiberglass windows and doors offer many advantages over competing materials such as wood, PVC, or aluminum. The pros of fiberglass outweigh the cons.

The Benefits of Fiberglass Windows and Doors