Minimum R Value Attic Insulation

Performance compliance walls ceilings floors.

Minimum r value attic insulation.

What i m talking about is a house with ducts in unconditioned space especially an unconditioned attic. 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. 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. 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.

The average recommended level is 14 inches of r49. The table below shows what levels of insulation are cost effective for different climates and. Insulating power or r value is only one factor to consider when building or improving a home to keep it comfortable. Ceiling insulation must be much higher at r 30 and a raised floor must be at least r 13.

R value is a measure of insulation s ability to resist heat traveling through it. The higher the r value the better the thermal performance of the insulation. R value measures how well certain building insulation materials can resist heat. Raised r 13 sog r 0 windows.

Prescriptive compliance form 405. There are many ways to retrofit a home with fiberglass and. Insulation level are specified by 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.

In zone 2 the average minimum requirement for attic insulation is 9 inches of r30 fill. You will need a higher r value of insulation if you live in the northeast than if you live in southern california. How much insulation in attic for zones 1 4. Recommended home insulation r values.

In zone 1 the average minimum requirement for attic insulation is 9 inches of r30 fill. 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. Maximum 20 of conditioned floor area. 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.

Our r value cognitive dissonance. The average recommended level is 17 inches of r60. Your home s age if your home is more than 10 year old you likely need more insulation. 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.

The higher the r value the greater the insulation performance. In general to optimally isolate an attic on average an r value of the insulation is required ranging from r 50 to r 60. When determining how much insulation you need don t guesstimate calculate. Where you live different climates require different insulation r values.