Two hands holding a pile of blown in attic insulation.

What Is Attic Insulation Made Of?


When it comes to keeping your home comfortable in the winter and summer, attic insulation plays a pivotal role. But have you ever wondered What attic insulation is made of? Let’s shed some light on the various materials that keep your living space comfortable year-round.

The Role of Attic Insulation

Before diving into the materials, it’s crucial to understand the importance of attic insulation. It acts as a barrier that minimizes the heat transfer between your home and the outside environment. The right insulation can lead to significant energy savings, improved indoor air quality, and a consistent temperature throughout your home.

Common Types of Attic Insulation

Fiberglass Insulation

Fiberglass is one of the most popular materials for attic insulation. Made from fine glass fibers, it’s available in batts and rolls or as loose-fill. Fiberglass is favored for its fire resistance, affordability, and ease of installation. However, proper safety gear is required during installation to prevent irritation from the glass fibers.

Cellulose Insulation

Cellulose is an eco-friendly option made from recycled paper products, primarily newsprint. It’s treated with fire retardants to enhance its safety. As loose-fill insulation, cellulose is excellent for filling in odd shapes and spaces in the attic, providing a high R-value per inch.

Spray Foam Insulation

Spray foam is a liquid polyurethane that expands into a foam, creating a tight seal against air leaks. There are two types: open-cell and closed-cell, with closed-cell providing a higher R-value. Spray foam is ideal for sealing gaps, but it’s more expensive than fiberglass and cellulose.

Mineral Wool Insulation

Mineral wool, known as rock wool and slag wool, is made from natural or synthetic fibers. It offers superior fire resistance and soundproofing capabilities. Mineral wool can be more expensive than fiberglass but is effective in areas requiring high-temperature insulation.

Radiant Barrier Insulation

Radiant barriers are reflective materials that reduce heat transfer from the roof to the attic space. While not traditional insulation, radiant barriers are particularly useful in hot climates to reflect the sun’s heat away from the living space.

Key Takeaways for Homeowners:

  • Diverse Materials: Attic insulation comes in various materials, including fiberglass, cellulose, spray foam, mineral wool, and radiant barriers. Each has its advantages and applications.
  • Energy Efficiency: The right attic insulation can lead to significant energy savings by maintaining a consistent indoor temperature.
  • Professional Consultation Recommended: Given the variety of insulation types and their specific applications, consulting with a professional can help you make the best choice for your home.

Practical Tips for Choosing Attic Insulation

  1. Consider Your Climate: The ideal insulation for your attic depends on your local climate. For example, radiant barriers are more beneficial in warmer regions, while thick layers of fiberglass or cellulose might be better in colder climates.
  2. Understand R-Values: The effectiveness of insulation is measured by its R-value. Higher R-values indicate better insulation. Choose a material that meets the recommended R-value for your area.
  3. Evaluate Your Attic Space: The layout and accessibility of your attic can influence the type of insulation best suited for your home.
  4. Think About Long-Term Benefits: While some insulation types may be more expensive upfront, their durability and energy savings can offer greater benefits over time.


Understanding what attic insulation is made of and the different types available is the first step toward achieving an energy-efficient and comfortable home. Whether you’re installing new insulation or replacing old material, it’s important to choose the right type for your needs and climate. Don’t hesitate to reach out to a professional attic insulation company for advice tailored to your specific situation.

Disclaimer: This blog post is for informational purposes only and is not intended as professional advice. The types of attic insulation mentioned are among the most common, but other materials are also available.