The attic is one of the largest sources of potential heat loss in a home and often one of the most neglected areas when it comes to insulation, especially in older homes. That's why adequate insulation is so important. Without proper attic insulation, your energy bills could be significantly higher. Whether your attic is and will remain unfinished, be used for storage, or be finished for use as living space, make sure that it is properly insulated with the right amount and kind of insulation.
If your attic is unfinished and you're insulating it for the first time, you will install insulation in the floor joists. If you're building a new home, install ceiling insulation up from underneath, before you put in drywall.
You should use faced insulation when a vapor retarder is needed. However, only unfaced insulation should be used near chimneys and flues.
You can also insulate your unfinished attic with blow-in insulation. Blow-in insulation can be installed by a professional contractor, or you can do it yourself. You can rent the necessary equipment from many home centers and rental centers.
If you're installing faced batts from underneath, hold the insulation up with one hand while stapling the flanges to the side or face of the joist every 6" - 8" with the other hand. Leave a little extra on each end to cover the top plate of the outside wall.
Blow-in insulation (also called loose fill or blowing wool insulation) is ideal for unfinished attics and attics with hard-to-reach areas. You can rent insulation blowing machines at many home improvement and equipment rental centers, or you may choose to hire a contractor to professionally install loose fill in your attic.
Like batts and rolls, blow-in insulation is also specified by R-value. It is a calculation of quantity of materials and rate of blowing needed to reach a desired density and height of material and cover the entire space. To achieve the desired R-value, it will be important to follow package labeling. The minimum number of bags per 1,000 square feet is based upon the net area of the space to be insulated.
Blow-in insulation is highly compressed in the bag. The blowing machine is designed to open up the insulation material, fluff it, and then blow it out through the hose at the rate you set to achieve the specified coverage and R-value.
A useful guide for installing the proper amount of blow-in insulation is to mentally divide the space into four equal parts. Then you can figure how many bags should go into each quarter of the space. For example, if you have 24 bags of insulation, you would blow six bags into each of the quadrants.
Fill three or four joist cavities by moving the hose to the right and left. Where possible, back away from the work to avoid packing the insulation. Be sure to get insulation to the top of the walls and low places. Don't cover eave vents.
Avoid using your hand as a baffle to direct the insulation as it exits the hose. Do this only when necessary to avoid packing.
Keep the hose close to the floor where insulation must go under obstructions like cross bracing and wiring. Insulation must be blown on both sides of these kinds of obstructions. If an obstruction has caused a low spot to occur, fill in the area.
Over the years, some insulation can become compacted and lose efficiency. If that's the case in your attic, you'll want to add a layer of insulation.
A finished attic is an excellent way to expand your living space with an additional bedroom, home office, game room, etc. A finished attic will require complete insulation just like any other room in your house, including the floor, ceiling, interior walls, exterior walls and knee walls. For instructions on how to properly insulate these areas of your home, click on Application Surface and select the appropriate links.
ComfortTherm® insulation is a lightweight, thermal and acoustical insulation made of long, resilient glass fibers bonded with an acrylic thermosetting Formaldehyde-free™ binder.
JM's Unfaced Insulation is a lightweight thermal and acoustical fiber glass insulation made of long, resilient glass fibers bonded with an acrylic thermosetting resin made without formaldehyde.
Johns Manville's Attic Protector® loose-fill fiber glass insulation is made for open attics to fill nonconforming spaces and hard-to-reach areas like corners, edges and around framing.
Johns Manville Climate Pro® loose-fill fiber glass insulation is made for installation in open attics to fill hard-to-reach areas like corners, edges and around framing.