Roof Insulation R Value Requirements

Recommended home insulation r values.

Roof insulation r value requirements.

Insulation level are specified by r value. The table below shows what levels of insulation are cost effective for different climates and. 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. Minimum insulation r value requirements non residential above roof deck.

Or component performance alternative of section c402 1 5 roof solar reflectance and thermal emittance fenestration in building envelope. 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. Minimum insulation r value requirements non residential above roof deck. 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. 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 regulations in the building code of australia bca that apply to home insulation are complicated. R value measures how well certain building insulation materials can resist heat.

When determining how much insulation you need don t guesstimate calculate. The higher the r value the greater the insulation performance. How much insulation does my home need. Know exactly how much you need with our project calculators.

Iecc 2015 requirements by climate zone 3. Non residential above roof deck this matrix provides the minimum insulation r values required by local and state municipalities. State only ma massachusetts 780 cmr chapter 13 5 r 30 state only mi michigan ashrae 90 1 2007 5 r 20 6 r 20 7 r 20 state only mn minnesota minnesota commercial state building code 6 r 30 7 r 35 please see disclaimer on back page. Minimum insulation r value requirements by state.

2015 code requires walls to be insulated with a minimum of r 20 or r 13 5 13 5 means r 13 cavity insulation plus r 5 insulated sheathing. As well as determining specific r value requirements for different parts of a home they also contain requirements for ventilation and various other related issues. The document was updated in 2020 and is available on the carlisle syntec website. The higher the r value the better the thermal performance of the insulation.

R value is a measure of insulation s ability to resist heat traveling through it.