How Much R Value Do I Need In My Attic

For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed in your attic to reach r 30 if you live in zones 2 or 3.

How much r value do i need in my attic.

You will need a. Learn more about insulation r values however the real answer is a bit more complex. Energystar gov for homes in the boise idaho area the insulation r value climate zone is 5. 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.

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. Existing 3 4 inches of insulation. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. If you look at the chart above you can see that the attic should achieve an r value between r38 and r60 depending on the current insulation levels.

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. This will allow you to add the needed insulation. R value of insulation by type. See the department of energy s doe ranges for recommended levels of insulation below.

Here are the r values per inch of the most common types of insulation. 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. Add insulation to attic. I ll also make sure to have an r 25 rating for my floor insulation.

There are two factors to consider when planning to insulate your attic. Where you live different climates require different insulation r values. Recommended insulation levels for retrofitting existing wood framed buildings. 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.

While some ceilings in the southwestern part of the united states require a minimum of r 19 insulation most attics or ceiling areas require a minimum of r 38 in the ceiling.