Minimum R Value Attic Insulation

In zone 2 the average minimum requirement for attic insulation is 9 inches of r30 fill.

Minimum r value attic insulation.

Insulation level are specified by r value. The higher the r value the greater the insulation performance. How much insulation in attic for zones 1 4. Where you live different climates require different insulation r values.

R value is a measure of insulation s ability to resist heat traveling through it. The average recommended level is 17 inches of r60. Raised r 13 sog r 0 windows. 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.

For block walls interior insulation must meet or exceed r 7 8 and exterior insulation must be r 6. If we put ducts in unconditioned space. 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. Our r value cognitive dissonance.

In general to optimally isolate an attic on average an r value of the insulation is required ranging from r 50 to r 60. There are many ways to retrofit a home with fiberglass and. The higher the r value the better the thermal performance of the insulation. You will need a higher r value of insulation if you live in the northeast than if you live in southern california.

Insulating power or r value is only one factor to consider when building or improving a home to keep it comfortable. 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. 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.

Ceiling insulation must be much higher at r 30 and a raised floor must be at least r 13. Know exactly how much you need with our project calculators. The table below shows what levels of insulation are cost effective for different climates and. 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.

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. Prescriptive compliance form 405. 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. When determining how much insulation you need don t guesstimate calculate.

R value measures how well certain building insulation materials can resist heat. In zone 1 the average minimum requirement for attic insulation is 9 inches of r30 fill. The average recommended level is 14 inches of r49. What i m talking about is a house with ducts in unconditioned space especially an unconditioned attic.