Fiberglass Windows vs. Vinyl Windows

When it comes to window replacements and new installations, there are two options on today’s market that are rapidly surpassing wood and aluminum as framing materials of choice among modern homeowners. The two materials are vinyl and fiberglass. So how do they compare in terms of quality, longevity, appearance, price and value?

Vinyl: The Pros

There are many benefits associated with vinyl windows, such as the low cost and sleek appearance of vinyl, which holds its color and never rots from exposure to the elements:

• Costs less: Vinyl windows cost less than fiberglass because there are fewer complexities involved in the vinyl-making process. On a per-window basis, fiberglass is approximately one-fourth more expensive than vinyl and this can add up if you replace many windows throughout your house. From a financial standpoint, vinyl windows are the more economical purchase for the homeowner who intends to occupy the same address for the next 10 to 15 years.
• No paint required: Each supply of vinyl is made with a resin that gives the material a permanent color. As such, the color of a vinyl window assembly is pre-determined at the time of purchase. When you choose vinyl, there is no need to concern yourself with color maintenance. In fact, paint will not adhere to a vinyl surface.
• Fade-resistant: Vinyl does not fade from exposure to ultraviolet rays. Unlike wood, which needs to be repainted or coated on a recurrent basis to maintain its color, vinyl retains its color throughout the lifespan of a window assembly. Regardless of how much sun exposure your windows receive, you can expect vinyl window frames to retain their color throughout the years that you own a property.
• Easier to install: Vinyl windows are generally easier to install than their fiberglass counterparts. For this reason, vinyl windows are easier to find at home-improvement stores, which typically do not stock fiberglass windows. As such, vinyl windows can be self-installed by the avid DIY enthusiast, though it is generally best to leave that work in the hands of professionals.
• Readily available: Vinyl windows are easier to come by than fiberglass ones. This is largely due to the fact that fiberglass windows are a relatively new option on the market and certain manufacturers have yet to embrace fiberglass as a frame material. You can find vinyl windows at various home-improvement outlets, whereas fiberglass windows usually must be ordered from specialty suppliers.
• Increases home resale value: By and large, modern homeowners like the appearance of vinyl window frames. While it may lack the vintage look of wood, vinyl is perceived of as being more durable due to its bug-resistance and rot-resistance. As such, vinyl windows can add value to your home if you decide to put your property back on the market.
• Lasts up to 30 years: Vinyl windows are typically good for up to 30 years. Given that most residential occupancies last anywhere from 10 to 15 years, vinyl windows can easily last through two generations of occupants at a given address. Once you install vinyl windows throughout your house, those windows could easily last through the next three decades.

Vinyl is a good choice for modern homeowners who live in moderate climates. Vinyl frames secure most types of glass.

Vinyl: The Cons

The main drawback of vinyl is its vulnerability to heat. If you remember record albums, you may know what would happen if they were left near a heat source. Here are some of the disadvantages of vinyl windows:

• Can warp under high temperatures: Vinyl will generally melt at temperatures over 165 degrees. While that may exceed even the hottest U.S. temperatures by about 50 degrees, this should give you some idea about vinyl’s key vulnerability. Melting aside, vinyl can slowly warp under extremely humid temperatures. If heat waves are a common summer occurrence in your area, vinyl windows might not be the most sound choice for your home.
• Expansion/contraction-prone amid changing temperatures: Even if a set of vinyl frames do not warp, they are still liable to expand and contract amid changing seasonal weather. Expansion occurs during the warmer months, and contraction occurs when the outside temperatures are cold. If the climate in your area veers between subzero winters and exceedingly humid summers, vinyl windows could easily lose their sealant quality and open/close functionality due to constant expansion and contraction issues.
• Possibly weak air seal: Vinyl windows are generally outperformed by fiberglass when it comes to sealing out wind drafts. This is due to the fact that fiberglass never expands or contracts and therefore forms a more air-tight fit along all inner and outer edges.
• Subpar insulation in the frame: The susceptibility of vinyl to expansion, contraction and warping effects renders the material less reliable when it comes to insulation. This can be a major issue for some homeowners, as the costs associated with insulation loss can account for up to a third of your monthly energy costs.

Overall, vinyl windows are not the right choice if you live in a humid climate or like to change your color scheme periodically.

Fiberglass: The Pros

Fiberglass windows have numerous advantages over competing options. As a material, fiberglass is stronger than vinyl or wood and resists all temperatures as well as the elements:

• Thinner frames: Fiberglass is a stronger material than vinyl. As such, fiberglass frames require less thickness. The superior strength of fiberglass is due to its chemical properties, which include glass in the makeup. Fiberglass windows of all styles, from double-hung assemblies to awnings, are thinner than their vinyl counterparts and fit more snugly into wall spaces.
• Superior insulation: Fiberglass windows offer superior insulation to vinyl ones. In the summertime, fiberglass frames are more effective at sealing out heat and protecting conditioned indoor air. During the cold months of winter, fiberglass windows insulate homes from freezing temperatures and help conserve indoor warmth. For homeowners, this translates to less reliance on HVAC units and reduced energy bills. The insulating factor also helps keep out unwanted noise from the outside.
• Temperature resistant: Heat does not have a softening effect on fiberglass windows, which retain their form in all climates and temperatures. No matter how hot the weather might get in your area, a fiberglass window frame will hold its shape. As such, fiberglass windows are impervious to warping effects or the expansion and contraction issues that are known to impact vinyl windows.
• Style variety: Fiberglass can be molded in a variety of textures and styles. In terms of appearance, fiberglass is a more versatile material than vinyl, which is known primarily for its sleek, shiny look. Fiberglass, by contrast, can be made to resemble vinyl or wood. If you need to replace a rotted wooden window frame, fiberglass could be a visually credible substitute that, unlike real wood, will never absorb water or attract termites.
• Increases home resale value: Today’s home buyers look for features that can weather the elements for many years into the future. Fiberglass is a stronger material than vinyl or wood and is therefore perceived by many homebuyers as the ultimate value in terms of windows. Even on an older home that originally featured wood frames, wood-like fiberglass frames could boost the home’s value in the eyes of potential buyers, who might view fiberglass as the ideal restoration material.
• Lasts up to 50 years: With an average lifespan that exceeds five decades, fiberglass windows last longer than most homeowners stay at the same property. With longer residencies typically ending at the 15-year mark, the same fiberglass windows could easily outlast three generations of occupants at a given property.

As a material that can look modern or classic, depending on how it is made, fiberglass is an ideal window framing material for new and old homes alike. Fiberglass frames secure most types of glass.

Fiberglass: The Cons

As a stronger material than vinyl, fiberglass requires more of an investment, especially if you need to have all the windows throughout your house replaced at the same time:

• Higher cost: Fiberglass costs higher than vinyl because its material makeup is of a higher quality. As a stronger and more robust material, fiberglass commands more value than vinyl, which is generally marketed as the lower-cost framing alternative for prospective window buyers. On average, the costs of a fiberglass window are higher than a vinyl window of comparative style, shape and measurements.
• Harder to find: As the newest option on the window market, fiberglass has yet to be universally adopted as a framing material. Since fewer manufacturers produce fiberglass windows, the option is harder to come by in catalogs or at home-improvement stores. In fact, fiberglass windows can rarely be found over-the-counter because, unlike vinyl, fiberglass windows are not suitable for DIY installation.
• Difficult to install: The installation of fiberglass windows requires advanced hand/eye coordination and a high degree of skill. For a fiberglass window assembly to fit within an allotted wall space, the measurements must be exact because, unlike vinyl, fiberglass is not a flexible material. Generally speaking, fiberglass windows should only be installed by a professional.
• Fades in sunlight: Fiberglass can fade over time through repeated exposure to ultraviolet rays. However, this will not be an issue if you opt to paint the fiberglass. On the upside, fiberglass can be painted, unlike vinyl, and this gives you even more stylistic options when you choose fiberglass frames.
• Needs periodic repainting: While fiberglass itself is not vulnerable to the elements, any paint or finish on the surface of fiberglass will ultimately wear down through repeated contact with heat and rain. Whether you choose to paint a fiberglass window frame or treat the surface to a finishing coat, the coat will need to be applied every six or eight years at roughly the same intervals that you would repaint your interior and exterior walls.

Fiberglass windows might be an excessive expense for younger home buyers who are liable to switch properties in less than 10 year’s time.

Fiberglass vs Vinyl Windows: A Quality Comparison

Vinyl and fiberglass both have their advantages. To determine which material might be better for your next set of windows, consider the quality of each material in the following categories:

1. Durability

How do fiberglass and vinyl compare in terms of strength and longevity?

• Fiberglass: Frames made of fiberglass retain form in all types of weather and generally last 20 years longer than vinyl windows.
• Vinyl: Vinyl frames can handle most climates throughout the U.S. but are liable to expand and contract amid seasonal extremes.

Overall, fiberglass is stronger and longer-lasting than vinyl and therefore has the advantage in terms of durability.

2. Appearance

Which type of material offers more versatility in terms of aesthetics?

• Fiberglass: Fiberglass can be produced in a variety of colors and appearances, including wood-like varieties. Fiberglass surfaces can also be painted.
• Vinyl: Vinyl is produced in a range of colors, though the material itself tends to always look like vinyl. Paint will not adhere to vinyl surfaces.

Fiberglass is more versatile because it can be painted and also specially made to mimic organic materials.

3. Temperature Resistance

Which material is more capable of withstanding climate extremes?

• Fiberglass: Fiberglass holds its form through the hottest and coldest of temperatures. A fiberglass frame can withstand UV degradation up to five times longer.
• Vinyl: Vinyl is more vulnerable to hot and cold temperatures. In cold weather, vinyl is liable to shrink. In humid conditions, vinyl tends to weaken.

Overall, fiberglass is more equipped to handle temperature extremes, which may or may not be an issue depending on the climate in your area.

4. Strength

Which of the two materials is stronger?

• Fiberglass: Fiberglass has eight times the strength of vinyl. Therefore, frames made of fiberglass require less thickness.
• Vinyl: Though strong in its own right, vinyl wears down sooner and is more susceptible to the elements.

In the strength department, fiberglass has the clear advantage over vinyl.

5. Stability

Which of the two is more stable?

• Fiberglass: Frames made of fiberglass are thermoset and unlikely to overheat.
• Vinyl: Frames made of vinyl are thermoplastic and likelier to overheat.

Overall, fiberglass offers more structural stability.

Are Fiberglass Windows Better Than Vinyl?

In terms of quality, fiberglass outperforms vinyl by the most objective criteria. Fiberglass is solid, versatile, long-lasting, impervious to the elements and resistant to all types of weather. That said, vinyl is sufficient in these areas under all but the most extreme environments.

Are Vinyl Windows Better Than Fiberglass in any way?

When it comes to strength and longevity, vinyl cannot be portrayed as superior to fiberglass. However, vinyl is a more affordable and available option for many homeowners, most of whom are perfectly happy with windows that can last for at least 30 years and that generally withstand all but the most extraordinarily humid conditions.

Cost Comparison: Fiberglass vs Vinyl Windows

Fiberglass windows can cost anywhere from 10 percent to 30 percent more than their vinyl counterparts. For a vinyl window that costs $425, a fiberglass counterpart could cost upwards of $575. When you multiply those prices by the number of windows you wish to replace and the labor for each installation, you could easily end up spending at least $1,200 more if you choose to go with fiberglass.

Consider Sunshine Contracting for Fiber Cement or Vinyl Window Installation

For more than 25 years, Sunshine Contracting has been the leading source for window installations in Northern Virginia. In the counties of Arlington, Fairfax, Prince William, Loudoun and Stafford, Sunshine Contracting performs window installations on residential properties. Contact Sunshine Contracting today for a free estimate.