Minimum R Value Attic Insulation

When determining how much insulation you need don t guesstimate calculate.

Minimum r value attic insulation.

Raised r 13 sog r 0 windows. Performance compliance walls ceilings floors. The insulation levels of an attic or of any part of a house are understood through the r value that is the value with which the insulating material is resistant to heat flow. R value measures how well certain building insulation materials can resist heat.

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. Your home s age if your home is more than 10 year old you likely need more insulation. In zone 2 the average minimum requirement for attic insulation is 9 inches of r30 fill. The higher the r value the better the thermal performance of the insulation.

I m in georgia iecc climate zone 3 where our current state code requires r 13 in exterior walls r 18 in attic kneewalls r 19 in floors and r 30 in ceilings. Insulation level are specified by r value. Where you live different climates require different insulation r values. How much insulation in attic for zones 1 4.

If structural sheathing covers 40 or less of the exterior continuous insulation r value shall be permitted to be reduced by no more than r 3 in the locations where structural sheathing is used. For block walls interior insulation must meet or exceed r 7 8 and exterior insulation must be r 6. In zone 1 the average minimum requirement for attic insulation is 9 inches of r30 fill. Our r value cognitive dissonance.

There are many ways to retrofit a home with fiberglass and. Ceiling insulation must be much higher at r 30 and a raised floor must be at least r 13. Recommended home insulation r values. R value is a measure of insulation s ability to resist heat traveling through it.

In general to optimally isolate an attic on average an r value of the insulation is required ranging from r 50 to r 60. Insulating power or r value is only one factor to consider when building or improving a home to keep it comfortable. The average recommended level is 17 inches of r60. What i m talking about is a house with ducts in unconditioned space especially an unconditioned attic.

If we put ducts in unconditioned space. 2015 code requires walls to be insulated with a minimum of r 20 or r 13 5 13 5 means r 13 cavity insulation plus r 5 insulated sheathing. The higher the r value the greater the insulation performance. Know exactly how much you need with our project calculators.

Maximum 20 of conditioned floor area. 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. Meet minimum r values given in table 402 1 1 frame walls r 13 block walls interior insulation r 7 8 exterior insulation r 6 ceilings. You will need a higher r value of insulation if you live in the northeast than if you live in southern california.