Roof Insulation R Value Requirements

State applicable energy ashrae zone minimum r value state local ms mississippi ashrae 90 1 2010 2r 20 3r 20 state local mo missouri 2012 iecc 4r 25 5r 25.

Roof insulation r value requirements.

State only ma massachusetts 780 cmr chapter 13 5 r 30 state only mi michigan ashrae 90 1 2007 5 r 20 6 r 20 7 r 20 state only mn minnesota minnesota commercial state building code 6 r 30 7 r 35 please see disclaimer on back page. Minimum insulation r value requirements by state. Specific insulation requirements of section c402 2 thermal requirements of either. The 2015 irc requires r 49 insulation for ceilings with attic spaces.

Building and energy codes almost always specify a required minimum r value for exterior walls and roof assemblies with above deck insulation so the minimum required r value in your local jurisdiction is something that you need to take into account when planning a building project. However there is an exception. Add insulation to attic. Existing 3 4 inches of insulation.

Climate zones 1 5 and 8 16 wall assemblies must not exceed a maximum u factor of 0 051 climate zones 6 7 wall assemblies must not exceed a maximum u factor of 0 065. These energy code r value requirements change from state to state and even city to city. Non residential above roof deck this matrix provides the minimum insulation r values required by local and state municipalities. R value based method of section c402 1 3 u c and f factor based method of section c402 1 4.

See the department of energy s doe ranges for recommended levels of insulation below. When determining how much insulation you need don t guesstimate calculate. Minimum insulation r value requirements non residential above roof deck. Minimum r value non residential above roof deck title.

Recommended insulation levels for retrofitting existing wood framed buildings. Mandatory minimum r 22 attic insulation unvented attics must be air sealed at roof deck eaves gables and penetrations. R value measures how well certain building insulation materials can resist heat. 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. Pa302 1 ceilings with attic spaces n1102 2 1 r402 2 1. The higher the r value the greater the insulation performance. Know exactly how much you need with our project calculators.

Gables to be insulated as exterior walls.