In our last post, we began our conversation as to what makes a home an Energy Star home. We talked about windows and the U rating – the indicator of how well a window product prevents heat from escaping. Today we’re going to talk about insulation which has a similar rating system for measuring performance known as the R-value.

The R-value of insulation is a measure of its thermal resistance to heat. An R-value rating is not limited to just insulation…you can measure and calculate an R-value for an entire wall (it’s insulation, sheathing, and framing members combined). Homeowners want to know if their homes are built with insulation materials that have the ability to resist heat flow. The higher the R-value, the better the insulated the home.

Proper insulation of a home is a key component of an Energy Star home. Regional standards dictate what R-values must be met in order to qualify for an Energy Star label.
Think of insulation as a large protective blanket that covers your entire house. When insulation is done properly, it can translate into higher comfort levels, higher resale value, lower bills, and long term durability.

Types of Home Insulation

There are five predominant types of insulation being used for residential construction these days:

• Fiberglass batts
• Sprayed cellulose
• Sprayed fiberglass
• Open cell foam
• Closed cell foam

Fiberglass batts insulation – Fiberglass batts have been around for decades and are certainly the most well know type of insulation on the market. The “batts” come in rolls, generally with kraft-faced backs (paper), and are rolled into the wall cavities and stapled in place. While fiberglass batts are generally the most affordable type of insulation, there are drawbacks to this type of insulation. Batts do not stop air transfer. They are not form fitting to fill cavities around pipes and other wall intrusions. Because of their construction limitations, they are prone to leaving gaps in wall cavities which diminishes their effect R-value.

Sprayed cellulose insulation – Sprayed cellulose insulation makes use of recycled materials like old newspapers and boxes. It’s a good insulation type for spaces and gaps that are difficult to fill because the insulation material is shredded into manageable nodules or granules, so a more even thickness is achieved. Because it is packed densely into wall cavities, it prevents air transfer and fills every vacant space giving the wall a nice effective R-value. It is also more sound resistant than fiberglass so it keeps your home insulated from exterior noise. It is also generally factory treated with a moldicide and a fire preventative.

Sprayed fiberglass – Sprayed fiberglass is the same material found in batts only it is blown into the wall cavities. Some manufactures of this technology add adhesive so that it stays in place and decreases air movement. Because it is sprayed in place instead of rolled in place, it does an adequate job of filling wall cavities. R-values of sprayed fiberglass vary by manufacturer. A common difficulty with sprayed fiberglass is that its installation method often creates bulges extending past framing members that prevent proper drywall installation.

Open cell foam insulation – Open cell foam insulation has an R-value similar to sprayed cellulose. It is generally cleaner to install than cellulose but is more toxic during installation. It is more expensive than cellulose or fiberglass. It fills wall cavities tightly which makes it effective in preventing air transfer.

Closed cell foam insulation – Closed cell foam insulation has foam cells tightly closed and packed together, filled with a gas to help the foam rise and expand, making it a good insulator. It generally has a much higher R-value than the other types of insulation but comes with a much steeper price tag as well.

Final analysis

At Weese Homes, we typically utilize the sprayed cellulose insulation for its superior insulative properties at a reasonable price point. While closed cell foam has a higher effective R-value, it is cost prohibitive in most applications at this time. Foam insulations are not as environmentally friendly because they require high energy use during manufacturing and are manufactured of fossil fuels and soy products. Cellulose on the other hand, is manufactured of recycled materials and uses only a negligible amount of energy during manufacturing.

Just how good is cellulose insulation at thermal resistance?  Check out this video from Applegate Insulation, our cellulose manufacturer: