Attic R Value Requirements

According to its r value or resistance to heat flow.

Attic r value requirements.

In calculating the r value of a multi layered installation the r values of the individual layers are added. Insulation level are specified by r value. R value based method of section c402 1 3 u c and f factor based method of section c402 1 4. 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.

The r value of thermal insulation depends on the type of material its thickness and density. Or component performance alternative of section c402 1 5 roof solar reflectance and thermal emittance fenestration in building envelope. See revised table area recommended r value attic 43 wall existing 13 wall new 21 floor over unconditioned space 21 basement wall 10. There are many ways to retrofit a home with fiberglass and.

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. Your home s age if your home is more than 10 year old you likely need more insulation. R value the greater the insulating effectiveness. R value is a measure of insulation s ability to resist heat traveling through it.

These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. The r value of thermal insulation depends on the type of material its thickness and its density. The higher the r value the greater the insulating effectiveness. 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.

Insulation is rated in terms of thermal resistance called r value which indicates the resistance to heat flow. 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. 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.

The higher the r value the better the thermal performance of the insulation. Specific insulation requirements of section c402 2 thermal requirements of either. The ildceo recommends the following r levels of insulation for this region. Recommended home insulation r values.

The higher the r value the better the insulation is in reducing heat flow. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. 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.