Roof Insulation R Value Code

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.

Roof insulation r value code.

Or component performance alternative of section c402 1 5 roof solar reflectance and thermal emittance fenestration in building envelope. Recommended home insulation r values. The document was updated in 2020 and is available on the carlisle syntec website. 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.

The international code council icc is a non profit organization dedicated to developing model codes and standards used in the design build and compliance process. Minimum insulation r value requirements non residential above roof deck is an extremely handy table for state and local jurisdictions in the united states. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. Insulation level are specified by r value.

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

The table below shows what levels of insulation are cost effective for different climates and. State applicable energy ashrae zone. State applicable code ashrae zone minimum r value state local al alabama 2015 alabama commercial energy code 2 r 25 3 r 25 state. While the r value for a material is typically given per inch the rsi is typically given per millimeter so please be aware that the r values and rsi values for the materials in the following table are not for equivalent thicknesses.

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. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. R value based method of section c402 1 3 u c and f factor based method of section c402 1 4. Where you live different climates require different insulation r values.

Your home s age if your home is more than 10 year old you likely need more insulation. Types of roof insulation. Specific insulation requirements of section c402 2 thermal requirements of either. Minimum insulation r value requirements non residential above roof deck.

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