Insulation r values vary based on the type thickness and density of the insulation material.
Attic insulation rating.
If your insulation doesn t measure up and you need more installation can be done as a weekend diy project or you can call a professional installer to handle the job.
Existing 3 4 inches of insulation.
If your current insulation is only 5 inches deep you ll need to add seven inches of insulation to achieve the 12 inch r 38 rating.
Let s say the insulation you ve selected has an r value of three per inch and you d like to achieve an overall value of r 36.
Add insulation to attic.
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.
Typically a higher insulation r rating means better climate control and better energy efficiency for your home.
Measure the area needing insulation.
Multiply the length times the width to determine the square footage of the space.
Recommended insulation levels for retrofitting existing wood framed buildings.
Measure the length and width of the area you need to insulate.
See the department of energy s doe ranges for recommended levels of insulation below.
An r value tells you how well a type of insulation can keep heat from leaving or entering your home.
Insulation ratings are measured in r values per inch of thickness.