Minimum Insulation In Roof

See the department of energy s doe ranges for recommended levels of insulation below.

Minimum insulation in roof.

There is an exception provided that allows the minimum thickness to be up to 1. 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. 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.

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. Existing 3 4 inches of insulation. Recognized by the iecc. Add insulation to attic.

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