Residential Roof R Value Requirements

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Residential roof r value requirements.

Closed cell spray foam has an r value of about r 6 or r 6 5 per inch. Note that there are many other requirements and exceptions to these figures depending on the state type of home and materials your home uses. Recommended home insulation r values. Minimum insulation r value requirements non residential above roof deck.

The document was updated in 2020 and is available on the carlisle syntec website. Floors over unheated spaces need to be insulated to a minimum of r 19 in zones 3 and 4. 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. Or component performance alternative of section c402 1 5 roof solar reflectance and thermal emittance fenestration in building envelope.

R value is a measure of insulation s ability to resist heat traveling through it. 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.

To meet r 38 in a roof or ceiling you would need about 6 or 6 5 inches of closed cell spray foam. What r value do i need. State applicable energy ashrae zone minimum r value state local ms mississippi ashrae 90 1 2010 2 r 20 3 r 20 state. 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.

Quick roofing guide to the international residential code. Minimum insulation r value requirements non residential above roof deck is an extremely handy table for state and local jurisdictions in the united states. 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. Below is a table outlining the basic r value requirements for walls roofs and floors.

Required r values for walls roofs and floors. 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. Insulation level are specified by r value. Quick roofing guide to the international building code.

The higher the r value the better the thermal performance of the insulation. Minimum insulation r value requirements by state.