Residential Roof R Value Requirements

State applicable energy ashrae zone minimum r value state local ms mississippi ashrae 90 1 2010 2 r 20 3 r 20 state.

Residential roof r value requirements.

Floors over unheated spaces need to be insulated to a minimum of r 19 in zones 3 and 4. The higher the r value the better the thermal performance of the insulation. Iecc 2015 requirements by climate zone 3. What r value do i need.

Browse product options or contact your local insulfoam rep to help you quickly pick the best products to simplify your building envelope needs and fit your project budget all with one supplier. There are two model building codes which form the basis of almost all of the building codes in the united states. Insulation level are specified by r value. Recommended home insulation r values.

Minimum insulation r value requirements non residential above roof deck. 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. R value based method of section c402 1 3 u c and f factor based method of section c402 1 4. Quick roofing guide to the international building code.

Minimum insulation r value requirements by state. Non residential above roof deck this matrix provides the minimum insulation r values required by local and state municipalities. The document was updated in 2020 and is available on the carlisle syntec website. Required r values for walls roofs and floors.

Quick roofing guide to the international residential code. 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. R value is a measure of insulation s ability to resist heat traveling through it. To meet r 38 in a roof or ceiling you would need about 6 or 6 5 inches of closed cell spray foam.

Minimum insulation r value requirements non residential above roof deck. Note that there are many other requirements and exceptions to these figures depending on the state type of home and materials your home uses. Roofing contractor license verification by state. Or component performance alternative of section c402 1 5 roof solar reflectance and thermal emittance fenestration in building envelope.

Specific insulation requirements of section c402 2 thermal requirements of either. R value state local al alabama 2015 alabama commercial energy code 2 r 25 3 r 25 state local ak alaska 2012 alaska building energy efficiency.