How Much R Value Do I Need In My Attic

Click the button to calculate the depth in inches and pounds of total insulation required for this job.
How much r value do i need in my 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. There are many ways to retrofit a home with fiberglass and. This will allow you to add the needed insulation. R value of insulation by type.
Where you live different climates require different insulation r values. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation. Input length width and desired r value of the area to be insulated. For example if your home has cellulose insulation at a depth of 8 inches between the joists the attic insulation has an r value of 3 7 times 8 or 29 6.
The short answer is as much as you can get and a good rule of thumb is to have a r value of 38 in your attic. To determine the r value of the insulation in your attic you need to know the r value of the type of insulation in your home and the thickness of the insulation. Learn more about insulation r values however the real answer is a bit more complex. Find your zone on the map and then use the chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces.
There are two factors to consider when planning to insulate your attic. Here are the r values per inch of the most common types of insulation. I ll keep in mind to have a minimum of r 49 in my attic since my house is located in a place with cold weather brrr brrr and brrr. 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.
You will need a higher r value of insulation if you live in the northeast than if you live in southern california. I ll also make sure to have an r 25 rating for my floor insulation. Recommended insulation levels for retrofitting existing wood framed buildings. Add insulation to attic.
See the department of energy s doe ranges for recommended levels of insulation below.