Minimum Roof Insulation R Value

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

Minimum roof insulation r value.

Add insulation to attic. Recommended insulation levels for retrofitting existing wood framed buildings. When determining how much insulation you need don t guesstimate calculate. 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.

Non residential above roof deck this matrix provides the minimum insulation r values required by local and state municipalities. Minimum insulation r value requirements by state. Hunter panels roofing tech topic r105. Your home s age if your home is more than 10 year old you likely need more insulation.

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 non residential above roof deck. Know exactly how much you need with our project calculators. Zone 6 requires an r 30 minimum which is 5 2 thick.

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. Basement walls require a minimum of either r 10 continuous or r 13 batted insulation. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. 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. 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 document was updated in 2020 and is available on the carlisle syntec website. Minimum insulation r value requirements non residential above roof deck is an extremely handy table for state and local jurisdictions in the united states.

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