Adding Insulation to the Attic
An under insulated attic can cost you a lot in unnecessary heating and cooling costs. Fortunately, updating your attic insulation is an easy, do-it-yourself project, and The Home Depot can show you how it's done using quality Owens Cornin Insulation products.
What’s your R-value?
Below are the U.S. Department of Energy recommended minimum R-values for your climate zone.
Your Climate Zone: 4
|Attics||2x4 Walls||2x6 Walls||Floors||Crawlspaces|
|Zone||4||R38 to R60||R13 to R15||R19 to R21||R25 to R30||R25 to R30|
Choosing the Right Insulation
Fiberglass insulation is sold in roll and batt form; both are available with or without kraft paper facing. Use the guide below to select the best insulation for your project.
Blown-In insulation is installed using blowing machines; best for adding additional insulation in attic.
Continuous rolls are easy to transport and can be cut to length; great for large areas.
Batts come in pre-cut lengths for faster installation and each package contains more square feet than rolls; ideal for framed cavities.
Faced insulation uses kraft paper vapor barriers to control moisture transmission between walls and floors.
Unfaced insulation does not have a vapor barrier; can be used over existing insulation in the attic, or where moisture control is not needed.
Measure your attic. Enter the square footage of your attic. If you don't know, enter your attic’s dimensions and the square footage will be calculated for you.
The following products are recommended for use in attics. Add items to your list, and you’ll be able to view, print or email your checklist when you’re done.
When adding a second layer of insulation in the attic, unfaced should always be used so that moisture is not trapped inside the insulation.
- Temporary flooring should be laid across the joists to provide some footing, and a temporary work light should be installed.
- Lay the insulation blanket at the outer edge of the attic space and work toward the center. This allows for more headroom in the center of the space, where cutting and fitting can be done. It's also a good idea not to get "insulated into a corner" where it will be hard to get back to the attic access.
- If the joist cavities are completely filled to the top of the joists, lay the new insulation in long runs perpendicular to the direction of the joists, and use leftover pieces for small spaces. If the cavity is not completely filled, use the appropriate thickness of insulation to fill it to the top, then add an additional layer of insulation in a perpendicular direction.
- The insulation should extend far enough to cover the tops of the exterior walls, but should not block the flow of air from the soffit vents. To make sure the soffit vents aren't blocked, install attic vents or baffles like Owens Corning raft-R-mate® Attic Rafter Vents, which assure unrestricted airflow from the soffit into the attic.
- Insulation should be kept 3" away from recessed lighting fixtures unless fixtures are marked "I.C." (Insulated Ceiling) — designed for direct insulation contact. If insulation is placed over an unrated fixture, it may cause the fixture to overheat and perhaps start a fire. The insulation should always be installed at least 3" away from any metal chimneys, gas water heater flues or other heat–producing devices.
- Fill the spaces between a masonry chimney and wood framing with a noncombustible material, such as unfaced EcoTouch® insulation, which will not burn.
NOTE: Do not leave faced insulation exposed. The facings on kraft-faced insulation will burn and must be installed in substantial contact with an approved interior finish as soon as the insulation has been installed. Facing must be installed in substantial contact with an approved ceiling, floor or wall material. Keep open flame and other heat sources away from facing. See package for warnings, fire hazard and instructions, or call 1-800-GET-PINK®. Check your local building codes for requirements in your area.
- Tape measure
- Utility knife
- Straightedge or 2 x 4 (for cutting insulation)
- Lightweight, squeeze-type stapler
- Work gloves
- Loose-fitting, long-sleeved shirt
- OSHA-approved safety glasses
- Disposable dust mask
- Portable work light
- Boards or sheets of plywood (provide a safe place to sit or kneel in an unfinished attic and a surface on which to cut the insulation)
- Pole or rake (for pushing insulation into out-of-the-way places in attics/flat ceilings)
Before you begin any insulation project make sure you:
- Seal any open penetrations
- Gather the necessary tools and wear protective gear listed above
- Always use a portable work light to ensure you have enough light in your work environment
- Leave EcoTouch® PINK® insulation in its wrapper until you are ready to use it
- Packaged insulation is highly compressed and expands greatly when the wrapper is opened
- Provide a safe place to sit or kneel in an unfinished attic and a surface on which to cut the insulation
- Use a pole or rake for pushing insulation into out-of-the-way places in attics/flat ceilings
- Properly insulate and seal attic access openings
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