Minimum Roof Insulation R Value

The higher the r value the greater the insulation performance.

Minimum roof insulation r value.

Recommended levels of 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. R value measures how well certain building insulation materials can resist heat.

Know exactly how much you need with our project calculators. Zone 6 requires an r 30 minimum which is 5 2 thick. 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. Basement walls require a minimum of either r 10 continuous or r 13 batted insulation.

Recommended insulation levels for retrofitting existing wood framed buildings. 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. Minimum insulation r value requirements non residential above roof deck. 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.

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. Your home s age if your home is more than 10 year old you likely need more insulation. Add insulation to attic. There are many ways to retrofit a home with fiberglass and mineral wool insulation.

The document was updated in 2020 and is available on the carlisle syntec website. 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. When determining how much insulation you need don t guesstimate calculate.

Minimum insulation r value requirements non residential above roof deck is an extremely handy table for state and local jurisdictions in the united states.