Minimum Roof Insulation R Value

Total minimum ratings to provide 1 75 btu or 0 50 watts per ft2 of conditioned floor area or provide 3 of energy used for mechanical and swh equipment and lighting dedicated outdoor air system per c406 6 or be equipped with an independent ventilation system designed to provide 100 outdoor air to each occupied space.

Minimum roof insulation r value.

When determining how much insulation you need don t guesstimate calculate. Minimum insulation r value requirements non residential above roof deck. Existing 3 4 inches of insulation. State applicable energy ashrae zone minimum r value state local ms mississippi ashrae 90 1 2010 2 r 20 3 r 20 state local mo missouri 2012 iecc 4 r 25 5 r 25 state only mt montana 2012 iecc 6 r 30.

Zone 6 requires an r 30 minimum which is 5 2 thick. Recommended insulation levels for retrofitting existing wood framed buildings. Know exactly how much you need with our project calculators. Recommended levels of insulation.

The document was updated in 2020 and is available on the carlisle syntec website. 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 higher the r value the greater the insulation performance. Minimum insulation r value requirements non residential above roof deck is an extremely handy table for state and local jurisdictions in the united states.

Basement walls require a minimum of either r 10 continuous or r 13 batted insulation. This exception will allow the minimum thickness to be 4 2 at the low point or 5 2 4 away from the drain on a per foot tapered system. Hunter panels roofing tech topic r105. There are many ways to retrofit a home with fiberglass and mineral wool insulation.

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. Minimum insulation r value requirements by state. 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. Add insulation to attic.

You will need a higher r value of insulation if you live in the northeast than if you live in southern california.