Minimum Wall Insulation R Value

Basement walls require a minimum of either r 10 continuous or r 13 batted insulation.

Minimum wall insulation r value.

High performance attics prescriptive attic options climate zone hvac duct insulation leakage radiant barrier. New wall or walls separating a sunroom from conditioned space shall meet the building thermal envelope requirements. 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. Wood frame wall r value for wood frame walls the minimum r value is 13 in zones 1 4.

Fiberglass batts for standard 2 4 walls are now available in low medium and high density products that range from r 11 to r 15. The higher the r value the better the thermal performance of the insulation. Or component performance alternative of section c402 1 5 roof solar reflectance and thermal emittance fenestration in building envelope. The minimum wall r value shall be r 13 in all zones.

While wall insulation is limited by the width of the studs different materials provide higher or lower r values. Quality insulation installation qii is now a prescriptive requirement. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. Zones 5 and 6 have a requirement of 20 and 7 and 8 are at 21.

R 408 31065 equivalent u factors. Include qii in the contractor scope as a hers rater will be inspecting the work. Recommended home insulation r values. R value based method of section c402 1 3 u c and f factor based method of section c402 1 4.

The table below shows what levels of insulation are cost effective for different climates 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. The minimum ceiling insulation r values shall be r 24 in zones 5 to 7. 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.

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. Zones 6 7 and 8 have a value requirement of 49. See the department of energy s doe ranges for recommended levels of insulation below. 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.

Specific insulation requirements of section c402 2 thermal requirements of either.