Minimum Residential Roof Insulation R Value

The document was updated in 2020 and is available on the carlisle syntec website.

Minimum residential roof insulation r value.

As well as determining specific r value requirements for different parts of a home they also contain requirements for ventilation and various other related issues. R value is a measure of insulation s ability to resist heat traveling through it. 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. Always double check with your local authority to confirm which code is currently in effect.

Recommended home insulation r values. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. The table below shows what levels of insulation are cost effective for different climates and. There are many ways to retrofit a home with fiberglass and.

What r value do i need. Injection foam insulation s higher r value with an r value of 4 0 to 5 1 per inch depending on the manufacturer pre expanded injection foam provides a higher r value than fiberglass or cellulose and it seals the building from air leakage at the same time. Non residential above roof deck this matrix provides the minimum insulation r values required by local and state municipalities. 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. Minimum insulation r value requirements non residential above roof deck is an extremely handy table for state and local jurisdictions in the united states. Insulation level are specified by r value. Your home s age if your home is more than 10 year old you likely need more insulation.

The regulations in the building code of australia bca that apply to home insulation are complicated. When determining how much insulation you need don t guesstimate calculate. For the purpose of insulation regulations australia is divided into many different. How much insulation does my home need.

Know exactly how much you need with our project calculators. Minimum insulation r value requirements by state. The higher the r value the greater the insulation performance. 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.

The higher the r value the better the thermal performance of the insulation.