Insulation: Choosing the Best Insulation for Your Home

What Is Fiberglass Insulation?

Fiberglass insulation is a common insulation option made from glass and sand spun into a fine fiber with a bonding agent. Fiberglass insulation is available in both batts and rolls and available in medium and high density. It's lower cost and high R-value makes it one of the most commonly used insulation materials.

What Are the Pros of Fiberglass Insulation?

Fiberglass comes in various forms, including blanket (batts and rolls), loose-fill insulation, and rigid boards and duct insulation. Homeowners can use fiberglass insulation for almost every home and room, and the high-density batts can offer high R-values. Most manufacturers utilize up to 60 percent recycled glass in their finished product.

What Are the Cons of Fiberglass Insulation?

Fiberglass insulation is usually bonded together with formaldehyde, which emits dangerous particulate matter (VOC) into one's home. This is particularly harmful to homeowners who have a forced-air heating or cooling system. This product is seldom recyclable and ends up in municipal landfills. It also requires gloves to install, as the small glass particles can be itchy and painful.

What Is Cellulose Insulation?

Almost all cellulose insulation is made from recycled newspapers. The cellulose is broken into small pieces and then fiberized. The final product can be packed tightly into building cavities to inhibit airflow substantially. Today, almost all manufacturers add borate to ensure fire and insect resistance.

What Are the Pros of Cellulose Insulation?

Most cellulose insulation is made from up to 85 percent recycled material, which dramatically reduces this type of insulation's carbon footprint. This bio-based insulation option can be blown into existing walls, reducing installation costs for home renovation projects.

What Are the Cons of Cellulose Insulation?

Cellulose insulation is at serious risk for moisture damage. Even a small amount of moisture can impact the resistance value while breaking down the paper fibers. As bio-based insulation, this is where cellulose falls short and can lead to mold growth.

What Is Spray Foam Insulation?

Spray foam is a chemical-based insulation product that expands up to thirty to sixty times its size from a mixing reaction caused during the spraying process. There are several types of foam insulation products, including polyisocyanurate, polystyrene, and polyurethane. When sprayed, they act as insulation and air barrier material that seals walls, floors, and ceiling cavities against air movement. Closed-cell spray foam is typically more expensive than open-cell spray foam. All foam types need to be mixed and sprayed on-site.

What Are the Pros of Spray Foam Insulation?

Unlike other insulation materials, spray foam insulation can fill cracks, gaps, and crevices on installation, thus improving your home's building envelope. It typically has the highest R-Value per square foot and can be installed over virtually any surface.

What Are the Cons of Spray Foam Insulation?

As a petrochemical product, spray foam insulation has an extremely high embodied energy footprint. It also emits harmful chemicals that can negatively affect the environment. One recent report by the EEFA finds that chemical foams might include dangerous toxins such as formaldehyde-based binders, halogenated flame-retardants, orthophthalates, isocyanates, and organotins. Workers installing spray foam insulation must wear protective masks at all times. 

What Is Mineral Wool Insulation?

Mineral wool insulation can be made from rock wool that consists of natural minerals like basalt or diabase. It can also be slag wool, made from blast furnace slag, or the waste matter that forms on the surface of molten metal.

What Are the Pros of Mineral Wool Insulation?

On average, mineral wool is made from 75 percent post-industrial recycled content, reducing its carbon footprint. Because it is made from metals, it doesn't require any chemical flame retardants and can be sold as either batts, rolls, or loose-fill insulation.

What Are the Cons of Mineral Wool Insulation?

Mineral wool insulation can release tiny metal slivers that can become lodged in the skin and are small enough to be inhaled. While this danger is usually most serious during installation, the inhaled slivers of mineral wool can irritate the alveoli and lead to lung disease.

What Is Natural Fiber Insulation?

Many natural products can be used for home insulation, including:

• Cotton (usually in the form of recycled denim)
• Sheep's wool
• Straw
• Hemp

These products are typically treated with borate or other chemicals or minerals to protect from fire, water, and insect damage.

What Are the Pros Natural Fiber Insulation

Many of these natural materials can be considered to be carbon positive, as they will absorb CO2 from the atmosphere as they grow. They do not off-gas will not contribute to VOCs in your home. They are all renewable materials and are biodegradable when disposed of. Cotton and wool are also excellent noise barriers. Wool and cotton insulation is easily handled and does not require protective gear for installation.

What Are the Cons Natural Fiber Insulation?

Moisture, fire, and insect damage can be a concern, especially if the product is untreated. These products can be significantly more expensive, and it can be a challenge to find installers who know how to insulate with natural fiber materials.