Insulation levels are specified by the R-value, which is a measure of the insulation's ability to resist heat flow. The higher the R-value, the better the thermal performance of the insulation. Generally, it is recommended to insulate attics to a height of R-38 or around 10 to 14 inches, depending on the type of insulation. If you suspect that your home is among the 90% of U. S.
households that don't have enough insulation, performing a simple inspection can help you determine your needs. For example, if you install R-19 fiberglass blocks on walls with 2 x 6 inch frames, with the uprights 16 inches in the center, double top plates, and other elements of a standard frame, the actual R value of the entire wall with the R-19 insulation will be approximately R-15. When adding insulation to your attic, leave a section uninsulated and only add insulation to areas that won't be used as storage. The recommended level of insulation for your attic depends on where you live. Uncoated insulation is ideal for adding to existing attic insulation, but paper-coated insulation is better for new spaces. To find out if you have enough insulation in your attic, measure the thickness of the insulation from top to bottom with a ruler. For those who incorporate insulation materials (our favorite option), make sure to install improvised depth gauges made from scrap wood in the attic.
In addition, since your attic already has blown insulation material, use only insulating materials without a coating and without a vapor retarder. In the case of existing houses, insulation costs are often much higher, so it is often difficult to justify such high levels of insulation. To maximize efficiency and ensure that your home is properly insulated, it is important to understand what type of insulation is best for your climate and how much you should install. The best way to determine this is by consulting an expert who can assess your home's needs and recommend an appropriate level of insulation.
