Fiberglass insulation installation for your home
Content updated: October 14th, 2026
Key takeaways
- Fiberglass insulation installation varies by type, using pre-cut batts, continuous rolls, or blown-in loose fibers to fill spaces in homes.
- Required thermal performance depends on climate, with recommended R-values ranging from R-30 in southern zones up to R-60 in northern zones.
- Improper fiberglass insulation installation or material compression can compromise efficiency over time.
- While fiberglass excels in damp areas, cellulose insulation offers greater cold-weather density and can be treated to help repel pests.
- Scheduling an inspection with a Terminix expert helps identify the best insulation strategy and R-value to help protect your home.
Jump to section:
What is fiberglass insulation made of?
How is fiberglass insulation installed?
How much fiberglass insulation does my home need?
Advantages and disadvantages of fiberglass
Fiberglass vs. cellulose insulation
Choosing the right insulation installation services
As a homeowner, you’re always looking for the most efficient and cost-effective ways to make your home comfortable. One of the best ways to achieve this is through attic insulation and crawl space insulation. Fiberglass insulation is a versatile and affordable option for many homeowners, but with all the options available on the market, is fiberglass insulation the optimal choice for your home? While Terminix only offers fiberglass insulation installation for crawl spaces, it is still a common choice for attic insulation.
Choosing between the different types of insulation means considering factors like what type of insulation you need, such as batt insulation or roll insulation, and thermal performance. Whether you're looking to improve your home's noise resistance or want extra protection to keep pests out, make an informed decision about which insulation is right for your home. Explore our comprehensive home services and learn how we can help protect your home.
What is fiberglass insulation made of?
Fiberglass insulation is made up of super-fine strands of recycled glass fibers. This insulation is available in three main forms: roll insulation, batt insulation, and blown-in insulation.
Fiberglass insulation is installed in attics, walls, and crawl spaces. Its effectiveness can be measured by its R-value, which depends on the thickness of the insulation. The higher the insulation's R-value, the better the insulation's thermal performance.
Roll vs batt vs blown-in fiberglass insulation
Roll insulation comes in long, continuous sheets and is best suited for large areas such as attics or floors where complete coverage is needed. Batt insulation is pre-cut into sections and works well with standard stud or joist spacing, making it ideal for walls, ceilings, and floors.
On the other hand, blown-in fiberglass insulation is applied using a machine that distributes loose fibers, allowing it to easily fill irregular spaces and cavities. When it comes to thermal efficiency, no single format is inherently "better." Their performance depends on proper installation.
How is fiberglass insulation installed?
The fiberglass insulation installation process depends on whether you choose batts, rolls, or blown-in loose fill.
- Batts and rolls: These are cut to fit standard cavity dimensions and installed with the paper barrier facing the conditioned living space. The material fits snugly between studs or joists, taking care not to compress the fibers, and secure it using staples and wire supports along the flanges if required.
- Blown-in: This is installed with a commercial blowing machine that pushes loose fiberglass fibers through a long hose directly into attics or enclosed wall cavities. This method requires installing depth markers to ensure an even, consistent thickness across the space.
How much fiberglass insulation does my home need?
The amount of attic insulation your home requires depends largely on your climate zone and local building codes. Thermal resistance is measured by the fiberglass R-value, which depends on the material's thickness and density. To calculate your total R-value, multiply the insulation thickness in inches by the material's specific R-value per inch.
Recommended R-values vary across geographical zones:
- Southern US / Zones 1–2: Typically require an attic rating of R-30 to R-38 (approx. 9–12 inches of fiberglass).
- Mid-Atlantic & Central US / Zones 3–4: Require R-38 to R-49 (approx. 12–15 inches).
- Northern US & Canada / Zones 5–8: Require R-49 to R-60 (approx. 15–18+ inches).
Advantages and disadvantages of fiberglass
Fiberglass insulation is popular for its versatility and affordability. It's an excellent insulator for both temperature and sound, and its availability as roll or batt insulation helps it adapt to a wide variety of spaces.
However, fiberglass insulation also has its drawbacks. The Occupational Safety and Health Administration (OSHA) of the U.S. Department of Labor mandates that all products containing fiberglass be labeled as both a potential carcinogen and a skin, lung, and eye irritant. Fiberglass is currently classified as an animal carcinogen, not a human carcinogen.
Another concern people have is the product's flammability. Because it's made of glass, the fiberglass itself won't burn, but it can melt if exposed to a sufficiently hot source. During a fiberglass insulation installation, it is often packed and installed with a paper shell, which can burn.
Caution should be taken when working with fiberglass insulation to prevent skin irritation and the accidental inhalation of loose fibers. Exposure to loose glass fibers typically occurs when fiberglass has been damaged or improperly installed. Additionally, fiberglass insulation can lose its R-value over time, especially if it becomes compressed or wet. While fiberglass can last decades, routine inspections every few years ensure it hasn't settled, retained moisture, or suffered pest damage.
Fiberglass vs. cellulose insulation
Fiberglass and cellulose insulation are both popular choices for attic insulation. Fiberglass insulation is made from fine strands of glass, while our cellulose insulation is made from at least 85% recycled paper.
Fiberglass insulation can be blown into attics or cut to fit, while cellulose can be blown into place or installed as batts. Cellulose insulation can also be treated with pesticides, while fiberglass cannot.
- Regional performance: Cellulose density gives it a slight edge in extreme cold climates by preventing airflow convective loops, whereas fiberglass performs exceptionally well in damp or humid regions because it does not absorb water easily. 1
- Cost difference: Fiberglass batts are generally among the most budget-friendly materials on the market, while loose-fill cellulose and blown fiberglass have slightly higher upfront installation costs due to specialized equipment requirements.1
Ultimately, choosing between fiberglass and cellulose insulation often comes down to your home's specific needs.
Choosing the right insulation installation services
Choosing the right insulation for your home can seem daunting, but it doesn't have to be. When deciding on insulation, weigh key factors such as your region's climate zone, budget, pest-resistance goals, and whether you are insulating an open attic space or the walls of a narrow crawl space.
Terminix offers insulation services for your attic and crawlspace to help protect your home. With our free attic insulation inspections and step-by-step treatment plans, our technicians are there from start to finish.
Get started with our cellulose attic insulation services today.