Your Guide to Cellulose Insulation: R-Value, Costs & Blow-In Benefits

Cellulose Insulation Guide

No doubt you’ve heard the phrase: “It’s what’s inside that counts.” Though it’s most often applied to people, the statement is equally true for homes – especially when it comes to the best insulation for a home.

Hiding within the unseen cavities of a building – walls, attics, ceilings, and even under the floors – is insulation, the material responsible for slowing the transfer of heat, sound, and even smell through a structure. High quality insulation improves a home’s efficiency, reduces energy costs and enhances overall comfort, and yet a 2024 report by the North American Insulation Manufacturers of America shows that 89 percent of U.S. single-family homes are under-insulated. 

Among the various types available, cellulose insulation is a great option for homeowners who value quality, efficiency, and sustainability. Eco-friendly, toxic-free cellulose is also the top choice for BuildLabs, a design and build company committed to precision craftsmanship and sustainable solutions for today's custom, luxury homes.

What is Cellulose Insulation? 

Cellulose insulation is a fibrous material made from recycled plant products, like wood and paper. Once the material is collected and processed into fibers, it is treated with non-hazardous chemicals (such as borate) to make it flame-retardant and resistant to pests and mold. There are two types of cellulose insulation: loose-fill and dense-pack. 

• Loose-Fill. This type of cellulose insulation consists of small, lightweight particles that are blown into open spaces, such as attics, using specialized equipment. Its loose structure allows it to fill gaps and conform to any irregularities in a space, ensuring thorough coverage over uneven surfaces. Because it is not compacted, loose-fill is primarily used in areas where gravity keeps it in place, again like flat or gently sloped attic floors. 

• Dense-Pack. Dense-pack insulation is composed of the same cellulose material but is installed under higher pressure, resulting in a tightly packed, dense form. This density minimizes settling and creates an almost solid thermal barrier that is particularly effective in enclosed spaces like walls and ceilings.

What are the Benefits of Cellulose Insulation? 

Beyond its outstanding thermal performance, cellulose insulation offers a range of benefits that make it a stand-out choice for the eco-conscious and sustainably-minded alike. 

• Eco Friendly. Cellulose insulation is one of the greenest insulation options, made with up to 85% recycled materials and using less energy to produce than fiberglass or foam. It lasts 20–30 years and is biodegradable, even doubling as mulch thanks to its borate treatment. A smart, eco-conscious choice that doesn’t skimp on performance.

• Energy Efficient. Cellulose insulation conforms to irregular spaces creating a dense, airtight barrier that reduces drafts and heat transfer.  With a high R-value – showing excellent thermal resistance – it keeps homes comfortable year-round while cutting energy use and lowering utility bills by as much as 20% (according to the U.S. Department of Energy). 

• Fire Resistant. Safety is a key feature of cellulose insulation, providing homeowners with even greater peace of mind. Cellulose is treated with non-toxic fire retardants like borates and holds a Class 1 fire rating, which means it resists ignition and slows the spread of flames. Instead of burning, cellulose insulations chars. It emits minimal smoke (<50 per the smoke development index ) and does not release toxic chemicals during combustion. 

• Sound Dampening. The dense fiber composition of cellulose insulation also absorbs sound. Whether you're looking to block outdoor noise or reduce room-to-room echos, cellulose creates a quieter, more peaceful indoor environment. 

• Pest and Mold Resistant. The same borate treatment that enhances fire resistance also acts as a natural deterrent to pests and mold. This dual benefit ensures a home is safe, quiet, and healthier for your family over the long term. 

Cellulose insulation is a great choice, but it's not without some potential drawbacks, like settling over time or holding moisture if it’s not sealed properly or in the event of damage, like from a burst pipe. However, these issues are often due to poor installation. Partnering with experienced professionals, like the certified team at BuildLabs, ensures proper application and minimizes these risks.

How is Cellulose Insulation Installed? 

Preparation

At BuildLabs, we ensure the job is done right from the start. Before installation, we thoroughly assess all areas needing insulation. This includes checking for moisture issues, like leaks or humidity, and ensuring the spaces are accessible for our equipment. Careful preparation ensures the insulation performs effectively and lasts for years to come.

Application

• Blowing. Blowing is BuildLab’s preferred application method as it’s widely regarded as the most effective way to apply cellulose insulation. Using advanced equipment, cellulose is blown into attics and wall cavities, ensuring thorough and even coverage. This process fills every gap, crevice, and irregular space, creating a seamless, dense thermal barrier with a higher R-value relative to other application methods. 
• Dense Packing. For walls and ceilings, cellulose is densely packed to achieve optimal thermal resistance, prevent settling, and maximize energy efficiency.
• Spraying. In some applications, a small amount of moisture or starch is added to spray cellulose insulation into place. This method helps the insulation adhere to surfaces like open wall cavities or ceilings, ensuring a consistent application and reducing gaps. The moisture also allows for better compaction, creating a seamless barrier once dried.

Each method is carefully chosen based on the specific needs of the project to ensure optimal performance and long-term durability.

Post-Installation

After the installation is complete, we inspect all insulated areas to confirm even distribution and proper density. With BuildLabs, you can trust that every detail has been checked and rechecked to deliver lasting comfort and energy efficiency in your home.

Recap:

Cellulose insulation offers many benefits: it's environmentally friendly, enhances energy efficiency, and improves home safety and comfort. Its unique properties make it a superior choice for homeowners committed to sustainability without compromising on performance.

Ready to upgrade your home’s insulation or to start your custom build? Contact BuildLabs today and learn how our expert installation of cellulose insulation can transform your living space into the peaceful and efficient haven you’ve always imagined. We look forward to hearing from you!