When it comes to improving the comfort and energy efficiency of your home, the attic is one of the best places to start. The Department of Energy (DOE) recommends that Southern homes have attics insulated with 13- to 14-inch insulation, or R-38, as a minimum. Northern homes should have attics with 16 to 18 inches of insulation or R-49. If your house isn't insulated with the recommended thickness, you may want to consider adding more insulation. Insulation levels are specified by the R value, which is a measure of the insulation's ability to withstand heat flow.
The higher the R value, the better the thermal performance of the insulation. The recommended level for most attics is R-38 or around 10 to 14 inches, depending on the type of insulation. Fiberglass and cellulose insulation have R values of 2.9 to 3.8 per inch, while sprayed foam insulation can go up to 8.0 per inch. According to the Department of Energy, it is recommended that attics have insulation of R-38 to R-49, or about 12 to 15 inches of fiberglass or cellulose.
When adding more insulation to an attic that already has some insulation, use uncoated insulation and place the rolls or blocks at right angles to the floor beams. If your attic does not have any type of insulation, use a coated insulator and place it in the space between the beams with the side of the paper facing down, towards the heated living room. When installing attic insulation, it's also a good idea to spray baby powder on exposed skin to reduce irritation caused by glass fibers. Now, a few things to know when buying insulation to add to an existing attic: make sure you don't have a paper back, as it can create a moisture trap; use uncoated insulation; and wear protective gear such as glasses, dust mask, gloves and long-sleeved shirt when installing fiberglass insulation. To install fiberglass insulation, place a temporary floor (with boards or plywood) on top of the beams and work from the outer edge of the attic to the center. If you used blown insulation in your attic for this project, use only uncoated block insulation without a vapor retarder.
You don't have to use the same type of insulation that currently exists in your attic; leave a section of the attic isolated and only add insulation to areas that won't be used for storage. The Department of Energy recently increased its attic insulation recommendation from R-38 to R-60, which in most attics means that a minimum of 19 inches of fiberglass block insulation or 22 inches of blown insulation is needed. Here's a quick checklist for determining how much attic insulation your home needs: if you can see the wooden beams on the ceiling in your attic floor, you don't have enough insulation; if you used blown insulation in your attic for this project, use only uncoated block insulation without a vapor retarder; and leave a section of the attic isolated and only add insulation to areas that won't be used for storage. In conclusion, when it comes to insulating your attic properly, there are several factors that need to be taken into consideration. The Department of Energy recommends that Southern homes have attics insulated with 13-14 inches or R-38 as a minimum while Northern homes should have attics with 16-18 inches or R-49 as a minimum. It is important to note that when adding more insulation to an existing attic, use uncoated insulation and place it at right angles to floor beams.
Additionally, when installing attic insulation it is important to wear protective gear such as glasses, dust mask, gloves and long-sleeved shirt when installing fiberglass insulation.
