Types of Insulation - Worcester, Boston

When insulating your home, you can choose from many types of insulation. To choose the best type of insulation, you should first determine the following:

• Where you want or need to install/add insulation
• The recommended R-values for areas you want to insulate.

Installing Insulation

The maximum thermal performance or R-value of insulation is dependent on proper installation.

When hiring a professional certified insulation installer:

• Obtain written cost estimates from several contractors for the R-value you need, and don't be surprised if quoted prices for a given R-value installation vary by more than a factor of two.
• Ask contractors about their air-sealing services and costs as well, because it’s a good idea to seal air leaks before installing insulation.

Blanket: Batt and Roll Insulation

Blanket insulation -- the most common and widely available type of insulation -- comes in the form of batts or rolls. It consists of flexible fibers, most commonly fiberglass. You also can find batts and rolls made from mineral (rock and slag) wool, plastic fibers, and natural fibers, such as cotton and sheep's wool. Learn more about these insulation materials.

Batts and rolls are available in widths suited to standard spacing of wall studs, attic trusses or rafters, and floor joists. Continuous rolls can be hand-cut and trimmed to fit. Manufacturers often attach a facing (such as kraft paper, foil-kraft paper, or vinyl) to act as a vapor barrier and/or air barrier. Batts with a special flame-resistant facing are available in various widths for basement walls and other places where the insulation will be left exposed. A facing also helps facilitate fastening during installation. However, unfaced batts are a better choice when adding insulation over existing insulation.

Loose-Fill and Blown-In Insulation

Blown-in insulation consists of small particles of fiber, foam, or other materials. These small particles form an insulation material that can conform to any space without disturbing structures or finishes. This ability to conform makes loose-fill insulation well suited for retrofits and locations where it would be difficult to install other types of insulation.

The most common types of materials used for loose-fill insulation include cellulose, fiberglass, and mineral (rock or slag) wool. All of these materials are produced using recycled waste materials. Cellulose is primarily made from recycled newsprint. Most fiberglass contains 20% to 30% recycled glass. Mineral wool is usually produced from 75% post-industrial recycled content. The table below compares these three materials.

Sprayed-Foam Insulation

Spray-foam insulation materials can be sprayed, foamed-in-place, injected, or poured. Some installations can have twice the R-value per inch of traditional batt insulation, and can fill even the smallest cavities, creating an effective air barrier.

Today, most foam materials use foaming agents that don't use chlorofluorocarbons (CFCs) or hydrochlorofluorocarbons (HCFCs), which are harmful to the earth's ozone layer.

Liquid foam insulation -- combined with a foaming agent -- can be applied using small spray containers or in larger quantities as a pressure-sprayed (foamed-in-place) product. Both types expand and harden as the mixture cures. They also conform to the shape of the cavity, filling and sealing it thoroughly.

Slow-curing liquid foams are also available. These foams are designed to flow over obstructions before expanding and curing, and they are often used for empty wall cavities in existing buildings. There are also liquid foam materials that can be poured from a container.

For information on types of insulation, contact Custom Insulation.

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