Minimum Roof Insulation R Value

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

Minimum roof insulation r value.

Recommended levels of insulation. R value measures how well certain building insulation materials can resist heat. 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. Your home s age if your home is more than 10 year old you likely need more insulation.

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. 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.

Minimum insulation r value requirements by state. Recommended insulation levels for retrofitting existing wood framed buildings. Hunter panels roofing tech topic r105. 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. 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. 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. Know exactly how much you need with our project calculators.

The document was updated in 2020 and is available on the carlisle syntec website. There are many ways to retrofit a home with fiberglass and mineral wool insulation. When determining how much insulation you need don t guesstimate calculate. 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.

The higher the r value the greater the insulation performance.