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.
Attic insulation rating.
Typically a higher insulation r rating means better climate control and better energy efficiency for your home.
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.
You ll need about 12 inches of insulation material.
Measure the length and width of the area you need to insulate.
Depending on where you live and the part of your home you re insulating walls crawlspace attic etc you ll need a different r value.
Insulation r values vary based on the type thickness and density of the insulation material.
Add insulation to attic.
An r value tells you how well a type of insulation can keep heat from leaving or entering your home.
Recommended insulation levels for retrofitting existing wood framed buildings.
See the department of energy s doe ranges for recommended levels of insulation below.
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.
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.
Existing 3 4 inches of insulation.
Measure the area needing insulation.