Fiberglass Insulation

When it comes to insulating homes and buildings, fiberglass insulation remains one of the most popular and trusted options in the industry. Known for its affordability, ease of installation, and proven thermal performance, fiberglass has been a go-to material for decades. Whether you’re a homeowner looking to improve energy efficiency or a contractor working on new construction, understanding fiberglass insulation can help you make informed decisions about your insulation needs.

In this guest post for Renton Spray Foam Insulation, we’ll break down what fiberglass insulation is, how it works, its pros and cons, and how it compares to other insulation options like spray foam.

What is Fiberglass Insulation?

Fiberglass insulation is made from extremely fine glass fibers. It’s typically composed of sand and recycled glass that are melted and spun into a wool-like material. The most common forms are:

Because fiberglass is naturally non-combustible and doesn’t absorb moisture easily, it’s a safe and reliable choice for a wide variety of insulation projects.

How Does Fiberglass Insulation Work?

The key to fiberglass insulation's effectiveness lies in its ability to trap air within the fibers. These pockets of air slow the movement of heat, keeping warm air inside during the winter and outside during the summer. In other words, it helps to maintain consistent indoor temperatures, reduce HVAC workload, and lower energy bills.

Fiberglass insulation is rated by R-value, which measures thermal resistance. The higher the R-value, the better the insulation’s effectiveness. Typical R-values for fiberglass batts range from R-11 to R-38, depending on the thickness and density.

Benefits of Fiberglass Insulation

Fiberglass insulation has remained popular for many good reasons. Here are some of the key benefits:

1. Cost-Effective

Fiberglass is among the most affordable insulation materials on the market. For budget-conscious homeowners or builders, it offers a great balance between price and performance.

2. Easy Installation

Batts and rolls can be quickly installed by a professional or an experienced DIYer. Blown-in options also provide flexible installation for attics and irregular spaces.

3. Fire Resistant

Since fiberglass is made from glass, it does not burn. This makes it a safe choice in terms of fire protection.

4. Good Soundproofing

In addition to thermal performance, fiberglass also helps reduce sound transmission, making your home quieter and more comfortable.

5. Widely Available

Fiberglass insulation is readily available at most home improvement stores and through insulation contractors, making it easy to source for nearly any project.

Drawbacks of Fiberglass Insulation

While fiberglass insulation has many advantages, it’s important to be aware of its limitations:

1. Can Irritate Skin and Lungs

Handling fiberglass without proper protective equipment can cause skin irritation and respiratory discomfort. It’s always best to wear gloves, masks, and long sleeves during installation.

2. Prone to Gaps

If not installed correctly, fiberglass batts can leave gaps or compress, reducing their effectiveness. This is especially true in older homes or areas with unusual framing.

3. Less Effective Air Seal

Unlike spray foam, fiberglass does not create an airtight seal. Air can still leak around or through the insulation unless other sealing measures are taken.

Fiberglass vs. Spray Foam: What’s the Difference?

As a visitor to Renton Spray Foam Insulation, you might be wondering how fiberglass compares to spray foam insulation. Here’s a quick comparison:

Spray foam offers a higher R-value and acts as both an insulator and air sealant. However, fiberglass insulation still holds its own for budget-friendly projects or where full air sealing isn’t necessary.

Is Fiberglass Insulation Right for You?

Fiberglass insulation can be a great choice for:

However, for those who want superior air sealing, moisture resistance, and energy efficiency, spray foam insulation may be a better fit — especially when professionally installed by a team like Renton Spray Foam Insulation.

Final Thoughts

Fiberglass insulation has stood the test of time for a reason. It’s affordable, widely available, and offers solid thermal and acoustic performance when installed properly. While newer technologies like spray foam have raised the bar in terms of efficiency and sealing, fiberglass remains a practical option for many residential and commercial applications.

If you’re weighing your insulation options or unsure which material is best for your space, don’t hesitate to reach out to the team at Renton Spray Foam Insulation. Even though we specialize in spray foam, we’re always happy to guide you toward the best insulation solution for your unique needs—fiberglass included!