Minimum R Value Attic Insulation

Insulation level are specified by r value.

Minimum r value attic insulation.

Know exactly how much you need with our project calculators. For block walls interior insulation must meet or exceed r 7 8 and exterior insulation must be r 6. There are many ways to retrofit a home with fiberglass and. In general to optimally isolate an attic on average an r value of the insulation is required ranging from r 50 to r 60.

R value is a measure of insulation s ability to resist heat traveling through it. What i m talking about is a house with ducts in unconditioned space especially an unconditioned attic. R value measures how well certain building insulation materials can resist heat. Maximum 20 of conditioned floor area.

The higher the r value the better the thermal performance of the insulation. Where you live different climates require different insulation r values. In zone 1 the average minimum requirement for attic insulation is 9 inches of r30 fill. In zone 2 the average minimum requirement for attic insulation is 9 inches of r30 fill.

The table below shows what levels of insulation are cost effective for different climates and. Your home s age if your home is more than 10 year old you likely need more insulation. When determining how much insulation you need don t guesstimate calculate. If we put ducts in unconditioned space.

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. 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. Raised r 13 sog r 0 windows. 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.

Insulating power or r value is only one factor to consider when building or improving a home to keep it comfortable. Performance compliance walls ceilings floors. 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 average recommended level is 14 inches of r49.

How much insulation in attic for zones 1 4. The higher the r value the greater the insulation performance. Recommended home insulation r values. Prescriptive compliance form 405.

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. The average recommended level is 17 inches of r60. Ceiling insulation must be much higher at r 30 and a raised floor must be at least r 13. 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.