Minimum Wall Insulation R Value

R value based method of section c402 1 3 u c and f factor based method of section c402 1 4.

Minimum wall insulation r value.

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. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. The table below shows what levels of insulation are cost effective for different climates and. R 408 31065 equivalent u factors.

Quality insulation installation qii is now a prescriptive requirement. The minimum wall r value shall be r 13 in all zones. Specific insulation requirements of section c402 2 thermal requirements of either. If structural sheathing covers 40 or less of the exterior continuous insulation r value shall be permitted to be reduced by no more than r 3 in the locations where structural sheathing is used to maintain a consistent total sheathing thickness.

High performance attics prescriptive attic options climate zone hvac duct insulation leakage radiant barrier. That means if you used foam it green closed cell which is r 7 per inch it s r value for a 3 5 deep wall cavity would be r 24 5. Recommended home insulation r values. Or component performance alternative of section c402 1 5 roof solar reflectance and thermal emittance fenestration in building envelope.

Include qii in the contractor scope as a hers rater will be inspecting the work. The mandatory minimum insulation in 2x6 framed walls is r 20. The minimum ceiling insulation r values shall be r 24 in zones 5 to 7. 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.

See the department of energy s doe ranges for recommended levels of insulation below. New wall or walls separating a sunroom from conditioned space shall meet the building thermal envelope requirements. While wall insulation is limited by the width of the studs different materials provide higher or lower r values. Basement walls require a minimum of either r 10 continuous or r 13 batted insulation.

R value is a measure of insulation s ability to resist heat traveling through it. The higher the r value the better the thermal performance of the insulation. 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. Wood frame wall r value for wood frame walls the minimum r value is 13 in zones 1 4.

Zones 6 7 and 8 have a value requirement of 49.