Keep your home a comfortable temperature year-round with attic insulation. Attic insulation blocks out the summer sun and winter chill, keeping your home cool in summer and warm in colder weather. The perks of insulating an attic, according to Energystar.gov, include reduced risk of ice dams on the roof during snow season; reduced noise; less pollen and dust and fewer insects in the home; and better humidity control—not to mention more comfortable temperatures and all the money you’ll save on utility bills. The heat from your furnace or cool air from your air conditioner will leak out through a poorly insulated attic, effectively sending your hard-earned money through the roof. The factors that affect the cost of attic insulation include the type of material used to insulate, the R-value you need in your climate, the square footage of your home, and the need to remove any old insulation.
Attic insulation is available in a variety of materials including fiberglass, mineral rock/wool, cellulose, spray foam, polystyrene and more. Different types of insulation have different R-values, explains Russ Lewis of Green Attics in Fort Worth, Texas. "Cellulose has an R-value of 3.2 per inch of depth, while fiberglass ranges from an R-value of 2 to 2.5 per inch of depth." says Lewis. Different climates and roof types may require different types of insulation; your specialist will help you determine the best insulation for your needs.
The main factor in determining the best type of insulation for your attic is the R-value required in your climate. The higher the R-value, the higher the thermal resistance of the insulation. This map from Energy.gov shows the recommended R-value based on your geographic location.
Cost per square foot
Many contractors charge per square foot for installing insulation in your attic. Factors that impact cost per square foot are the type of insulation you are installing, the square footage of your attic, the accessibility of your attic, and the need to remove old insulation. Mitigating and removing asbestos or mold will also add to the cost. If your insulation is in good condition, the specialist can install the new insulation on top of the existing insulation. Here are two examples of insulation cost per square foot.
- Cellulose blown-in insulation: $1.20-$1.25 per square foot from Juan Gutierrez of Capital Insulation in Tacoma, Washington. Price includes labor.
Total cost to customer: $1,950 from Jim Knipe of Superior Remodels in Newtown, Connecticut.
Applied closed cell foam with R-value 21 to attic rafter.
$3.25 per square foot.
Total project time: 6 hours.
Insulation removal costs
Before new insulation can be installed, rotten or damaged insulation must first be removed, and how it has to be removed—by hand or by machine— will affect cost. Rodent droppings and nests, water damage, and wood chips from shoddy roofing jobs can all damage insulation and make it more difficult to remove. If there are wood chips in the insulation, explains Gutierrez with Capital Insulation, it must be bagged by hand rather than sucked out with an industrial machine, which takes more time. Here are some examples of cost: