R value of insulation by type.
How much r value do i need in my attic.
How much attic insulation do i need.
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.
Energystar gov for homes in the boise idaho area the insulation r value climate zone is 5.
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.
I ll also make sure to have an r 25 rating for my floor insulation.
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.
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.
See the department of energy s doe ranges for recommended levels of insulation below.
Recommended insulation levels for retrofitting existing wood framed buildings.
There are two factors to consider when planning to insulate your attic.
Where you live different climates require different insulation r values.
Things needed dust mask.
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.
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.
Here are the r values per inch of the most common types of 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.
Existing 3 4 inches of insulation.
Learn more about insulation r values however the real answer is a bit more complex.
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.
These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation.
You will need a.