Minimum R Value Attic Insulation

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

Minimum r value attic insulation.

In zone 2 the average minimum requirement for attic insulation is 9 inches of r30 fill. How much insulation in attic for zones 1 4. 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. 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. Insulation level are specified by r value. Our r value cognitive dissonance. There are many ways to retrofit a home with fiberglass and.

When determining how much insulation you need don t guesstimate calculate. R value measures how well certain building insulation materials can resist heat. Maximum 20 of conditioned floor area. Performance compliance walls ceilings floors.

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. 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 table below shows what levels of insulation are cost effective for different climates and.

In zone 1 the average minimum requirement for attic insulation is 9 inches of r30 fill. 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. The average recommended level is 14 inches of r49. Recommended home insulation r values.

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. Raised r 13 sog r 0 windows. If we put ducts in unconditioned space.

For block walls interior insulation must meet or exceed r 7 8 and exterior insulation must be r 6. R value is a measure of insulation s ability to resist heat traveling through it. Ceiling insulation must be much higher at r 30 and a raised floor must be at least r 13. Your home s age if your home is more than 10 year old you likely need more insulation.

The average recommended level is 17 inches of r60. 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. Prescriptive compliance form 405.