Residential Roof R Value Requirements

Or component performance alternative of section c402 1 5 roof solar reflectance and thermal emittance fenestration in building envelope.

Residential roof r value requirements.

Non residential above roof deck this matrix provides the minimum insulation r values required by local and state municipalities. Minimum insulation r value requirements non residential above roof deck. There are two model building codes which form the basis of almost all of the building codes in the united states. 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.

Minimum insulation r value requirements by state. Required r values for walls roofs and floors. R value based method of section c402 1 3 u c and f factor based method of section c402 1 4. R value is a measure of insulation s ability to resist heat traveling through it.

Iecc 2015 requirements by climate zone 3. Specific insulation requirements of section c402 2 thermal requirements of either. Closed cell spray foam has an r value of about r 6 or r 6 5 per inch. 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.

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. The higher the r value the better the thermal performance of the insulation. 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 r value requirements non residential above roof deck.

Roofing contractor license verification by state. Insulation level are specified by r value. To meet r 38 in a roof or ceiling you would need about 6 or 6 5 inches of closed cell spray foam. State applicable energy ashrae zone minimum r value state local ms mississippi ashrae 90 1 2010 2 r 20 3 r 20 state.

Recommended home insulation r values. Note that there are many other requirements and exceptions to these figures depending on the state type of home and materials your home uses. What r value do i need. Below is a table outlining the basic r value requirements for walls roofs and floors.

Quick roofing guide to the international building code. The document was updated in 2020 and is available on the carlisle syntec website.