The attic is by far the most important area of your home to have insulated. We suggest homeowners make certain their attic is well insulated before insulating any other area of their home. All too often homeowners believe they have adequate insulation in their attic and in fact only have a small fraction of what they should have. Like many things in life, some people rather not know and just presume things are fine, all the while their heating and cooling bills are unreasonably high or they’re suffering with an uncomfortable home. Check your attic insulation!
Attic insulation works both during the summer and during the winter. In summer it reduces heat from coming into the home and in winter it holds heat from rising out. The result is a more comfortable home with lower energy bills year-round. For a better understanding of how insulation works, see our section How Insulation Works.
The attic can be insulated using rolled-in fiberglass, blown-in fiberglass or blown-in cellulose. Your choice, but we strongly feel the cellulose is the best insulation material to choose from. Cellulose is more effective, more efficient, longer-lasting and safer than fiberglass. For more information on materials, see our sections on Cellulose vs. Fiberglass, or our section on Blown vs. Rolls.
Many homeowners believe they have sufficient insulation already in their attic. Ideally, you want to have a performance rating of R-38. Cellulose develops an R-38 rating with approx. 10″ of thickness, while fiberglass requires up to 16″ in order to attain the same R-38 rating.
The performance of an insulation material is measured by “R-Value”, where the “R” stands for Resistance. The thicker the insulation, the greater/higher it’s R-value and performance.
Asphalt-composition roofs are much hotter than wood-shingle or wood-shake roofs of the past. Think about a park bench basking in the summer sun, if it were made of wood and you sat on it, it would be warm but certainly not terribly hot. If the same bench where made of rock, it would be significantly hotter! Also, the older wood-based roofs had natural ventilation, by comparison the asphalt-composition roofs are much more sealed. Asphalt-composition roofs are the most common and hottest roofs on homes.
Attics that have whirly-birds, fans, dormers and vents tend not to get as hot. By keeping the attic cooler, the insulation doesn’t have to work as hard. If you’re attic is well ventilated, you may be fine with just bringing it up to R-30.
A higher pitched roof has more “stand-up” area inside it. While this makes it easier to walk around, it also provides more area and space for the heat to rise. The further the heat is away from the ceiling and insulation, the better. So if you have a very tall-pitched/steep roof, here again you may be fine with just an R-30.
A darker color gets hotter than a lighter color, something few homeowners consider when selecting the color of their roof. A black-colored roof will absorb much more heat into an attic then a light-grey colored roof.
A tall shade tree, high canyons surrounding the house or other structures can often offer a nice break to keep the roof from being baked by the sun. Quite often homeowners get that large tree trimmed and suddenly their home is noticeably warmer! Shade trees can be invaluable for both looks and staying cooler in the summer!
Homeowners often express concern about working in the attic after it has been blown with insulation. The good news is that homeowners often report that working in blown insulation is not nearly as difficult as they had imagined. The loose-fill material can simply be displaced or shifted out of the way temporarily when areas need to be worked in. Also, non-itchy cellulose provides an R-38 with only 10″, which is much easier to work in then the 16″ of very itchy fiberglass required to achieve the same R-38 rating.