Minimum Roof Insulation R Value

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

Minimum roof insulation r value.

Know exactly how much you need with our project calculators. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. Add insulation to attic. 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.

Basement walls require a minimum of either r 10 continuous or r 13 batted insulation. Minimum insulation r value requirements non residential above roof deck is an extremely handy table for state and local jurisdictions in the united states. The document was updated in 2020 and is available on the carlisle syntec website. 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.

Recommended insulation levels for retrofitting existing wood framed buildings. Zone 6 requires an r 30 minimum which is 5 2 thick. R value measures how well certain building insulation materials can resist heat. Recommended levels of insulation.

Non residential above roof deck this matrix provides the minimum insulation r values required by local and state municipalities. 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. Minimum insulation r value requirements non residential above roof deck. 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 by state. Existing 3 4 inches of insulation. 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. Your home s age if your home is more than 10 year old you likely need more insulation.

The higher the r value the greater the insulation performance.