What Areas of My Home Should I Insulate?
To achieve the maximum thermal efficiency and comfort it is important to insulate any space were energy could be lost. Click the numbered spots below to view places in a typical house where insulation should be installed.
Insulation is not just for attics and outside walls.
Insulation should also be installed in other areas of your home such as floors over unheated spaces, basement walls, floors above vented crawlspaces, cathederal ceilings, floors over unheated garages or porches, knee walls and in between interior walls, ceilings or floors for extra sound control.
In addition to meeting Federal, state and local building codes energy efficiency standards, a well-insulated home is on of the most cost effective ways to save energy and reduce heating and cooling bills while adding to the home's therma and acoustical comfort.
Attics and Flat Ceiling
Installing fiber glass or rock/slag wool insulation in attics and flat ceilings makes the home more resistant to energy loss, lowers energy bills, and reduces pollution related to energy production. The most common products for attics and flat ceilings are R-30 and R-38 fiber glass or mineral wool batts. Note that these products are full width 16" or 24" wide. This is to assure that the insulation fills the spaces between the ceiling joists or bottom chords of trusses and also extends above and closes over most wood members.
To achieve R-values of R-38 and higher, two layers can be used and their R-value combined. For example, an R-19 batt added to an R-30 will yield an R-49. When installing a second layer, always use unfaced insulation. Using a vapor retarder can trap moisture between two layers. Also, it is recommended that the second layer be applied across the joists.
Fiber glass or mineral wool losse-fill insulation can also be used. Loose-fill is designed for open blow applications and applied through pneumatic means using a mechanical blowing machine. The insulation can be installed to an R-value. However, to achieve the correct R-value it is extremely important that the proper amount and minimum thickness of insulation be installed. Because R-values per inch vary by product, always check the manufacturer's recommended installation instructions and install the proper amount. Inches alone may not determine R-Value.
A combination of batts and loose-fill insulation is another alternative. A batt can be installed during the initial construction process, and a layer of blown insulation can be added later. This method is particularly effective in homes with roof trusses or hard-to-reach "nooks and crannies" - places that are prime for energy loss.
