Finished Attic Insulation R Value

Of combined fiberglass and foam insulation.

Finished attic insulation r value.

Add insulation to attic. Recommended insulation levels for retrofitting existing wood framed buildings. The higher the r value the greater the insulation performance. Know exactly how much you need with our project calculators.

Existing 3 4 inches of insulation. This means you can have a combined r value ranging from r 23 to r 31 with only 5 1 2 in. Rigid foam sheeting has an r value ranging from r 5 to r 10 per inch of thickness. R value measures how well certain building insulation materials can resist heat.

Typical recommendations for exterior walls are r 13 to r 23 while r 30 r 38 and r 49 are common for ceilings and attic spaces. Where you live different climates require different insulation r values. If you look at the chart above you can see that the attic should achieve an r value between r 38 and r 60 depending on the current insulation levels. Install air chutes before installing insulation why your roof needs air chutes.

Your home s age if your home is more than 10 year old you likely need more insulation. In addition to climate r value also depends on the age of your home. There are many ways to retrofit a home with fiberglass and. For homes in the seattle washington area we ve already established that the correct insulation r value climate zone is 4.