Attic R Value Requirements

The r value of thermal insulation depends on the type of material its thickness and its density.

Attic r value requirements.

The r value of thermal insulation depends on the type of material its thickness and density. Sps 322 32 1 b b an attic access cover shall be weatherstripped and insulated to a level equivalent to the insulation on the surrounding surfaces when the. In general to optimally isolate an attic on average an r value of the insulation is required ranging from r 50 to r 60. Installing more insulation in your home increases r value and the resistance to heat flow.

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. The higher the r value the better the thermal performance of the insulation. Recommended home insulation r values. R value the greater the insulating effectiveness.

According to its r value or resistance to heat flow. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. Insulation r value requirements for usa. See revised table area recommended r value attic 43 wall existing 13 wall new 21 floor over unconditioned space 21 basement wall 10.

R value is a measure of insulation s ability to resist heat traveling through it. The higher the r value the better the insulation is in reducing heat flow. Sps 322 32 1 a a r 38 will satisfy the ceiling r value requirement for a dwelling where the full height of uncompressed r 38 insulation extends over the wall top plate at the eaves. Insulation level are specified by r value.

The ildceo recommends the following r levels of insulation for this region. The insulation levels of an attic or of any part of a house are understood through the r value that is the value with which the insulating material is resistant to heat flow. Or component performance alternative of section c402 1 5 roof solar reflectance and thermal emittance fenestration in building envelope. Your home s age if your home is more than 10 year old you likely need more insulation.

Specific insulation requirements of section c402 2 thermal requirements of either. R value based method of section c402 1 3 u c and f factor based method of section c402 1 4. Insulation is rated in terms of thermal resistance called r value which indicates the resistance to heat flow. In calculating the r value of a multi layered installation the r values of the individual layers are added.

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. There are many ways to retrofit a home with fiberglass and. 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.