Depending on where you live and the part of the house you are going to insulate (walls, mezzanines, attics, etc.). Typical recommendations for exterior walls are R-13 to R-23, while R-30, R-38, and R-49 are common for roofs and attics. Insulation indices are measured in R values per inch of thickness. An R value indicates how well a type of insulation can prevent heat from entering or leaving your home.
The R values of insulation vary depending on the type, thickness and density of the insulation material. A higher R insulation rating usually means better climate control and greater energy efficiency for your home. A higher insulation R-value usually also means a higher price. Insulation levels are specified using the R value. The R value 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 to insulate them to R-38 or approximately 10 to 14 inches, depending on the type of insulation. Just like in attics or anywhere else in the house, adding more layers of insulation to exterior walls is key to having a higher R value and better performance thermal. The attic is the easiest place to add insulation to improve your comfort and the energy efficiency of your home.
No matter what type of insulation you currently have in your attic, a quick way to determine if you need more is to look across your attic. It is important that the insulation is distributed evenly, without low spots; sometimes there is enough insulation in the center of the attic and very little along the eaves. For example, if your attic already has fiberglass insulation blankets installed, you can improve your R value by installing blown cellulose insulation in the top of the blankets. Search for your area on the map and then use the insulation R-value table above to determine the level of insulation you need to properly insulate your attic, walls, floors, and mezzanines.
Now that you've air-sealed the attic and basement, check the attic's insulation levels and add more if necessary. Once you find the area of your house on this map, you can use the following table of R values for insulation to determine the minimum R value your insulation should have. By adding additional insulation, there is no need to use the same type of insulation that currently exists in the attic.
