Minimum Residential Roof Insulation R Value

R value measures how well certain building insulation materials can resist heat.

Minimum residential roof insulation r value.

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. The higher the r value the greater the insulation performance. The higher the r value the better the thermal performance of the insulation. When determining how much insulation you need don t guesstimate calculate.

Your home s age if your home is more than 10 year old you likely need more insulation. Always double check with your local authority to confirm which code is currently in effect. Insulation level are specified by r value. There are many ways to retrofit a home with fiberglass and.

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. The regulations in the building code of australia bca that apply to home insulation are complicated. Non residential above roof deck this matrix provides the minimum insulation r values required by local and state municipalities. What r value do i need.

Recommended home insulation r values. For the purpose of insulation regulations australia is divided into many different. The table below shows what levels of insulation are cost effective for different climates and. Minimum insulation r value requirements non residential above roof deck is an extremely handy table for state and local jurisdictions in the united states.

Know exactly how much you need with our project calculators. Minimum insulation r value requirements by state. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. Minimum insulation r value requirements non residential above roof deck.

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. Where you live different climates require different insulation r values. High r value with foam insulation in pennsylvania sprayed polyurethane foam has an aged r value of approximately 6 0 per 1 inch thickness depending on the particular formulation and application higher values have been achieved enabling it to provide more thermal resistance with less material than any other type of commercial insulation. 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.

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.