With cooler months approaching and fuel prices rising, it’s a good idea to make sure buildings are well-insulated. For residential structures, a good place to check is in the attic.

Attic insulation prevents heat from entering the home in the summer and escaping in the winter. The most common and economical attic insulation are fiberglass blankets, which fit between the joists. These blankets come in batts or rolls, and can be foil-faced, kraft-faced, or un-faced. Further options include different R-values(a higher R-value indicates more insulating quality). Common R-values for fiberglass insulation include:

• 3-1/2" – R13
• 6" – R19
• 9" – R30
• 12" – R38

Another option for attics is Spray Polyurethane Foam (SPF) insulation, which is sprayed in the area to be insulated and fills uneven cavities. Because SPF adheres directly to the framing, it can prevent moisture condensation and mold growth. Also, SPF has soundproofing qualities, especially when used in metal buildings.

When looking to insulate walls, there are many option available, including rock wool, fiberglass, cellulose, vermiculite, perlite, or blown-in foam. If the structure was not previously insulated, retrofitting with insulation may be difficult, but a good option is to use blown-in loose fill. Although this method can leave many areas uninsulated (such as pockets for window sash cords), it is relatively easy to install without causing too much damage to the existing structure. One common method for installation is to drill holes 16" O.C. at the midpoint and top of the wall from the outside.

Rigid insulation, such as foam board, can also be used to insulate walls. It can be purchaned in 4' x 8' sheets.

Not all insulation is applied on a structure’s interior. Exterior Insulation and Finish Systems, such as Expanded Polystyrene (EPS) are used on the outsides of buildings. EPS can be factory applied or field installed, and is available in a variety of colors and designs.

With the growing focus on climate change and the increasing cost of heating fuel, thermal insulation is an important consideration in both new and existing structures.

RSMeans Building Construction Cost Data contains material and labor costs for all of the insulation systems listed in this article