Minimum Insulation In Roof

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 in roof. Add insulation to attic. Existing 3 4 inches of insulation. Minimum insulation r value requirements by state. Adhered bituminous membrane minimum requirements adhered single ply membrane minimum requirements see notes below for required perimeter and corner enhancements2 3 2 3see notes below for required perimeter and corner enhancements insulation type thickness 4 x 4 4 x 8 insulation type thickness 4 x 4 4 x 8.

Zone 6 requires an r 30 minimum which is 5 2 thick. Minimum insulation r value requirements non residential above roof deck. Recommended insulation levels for retrofitting existing wood framed buildings. Non residential above roof deck this matrix provides the minimum insulation r values required by local and state municipalities.

There is an exception provided that allows the minimum thickness to be up to 1. Hitting amazing levels of 0 13w m will need 300mm of mineral wool or 180mm of rigid foam. See the department of energy s doe ranges for recommended levels of insulation below. Achieving a u value of 0 20w m meaning your roof will be better insulated than your walls will need 120mm thickness of rigid foam or 200mm of mineral wool or natural insulation.