Minimum R Value For Attic Insulation

In zone 1 the average minimum requirement for attic insulation is 9 inches of r30 fill.

Minimum r value for attic insulation.

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. Performance compliance walls ceilings floors. R value is a measure of insulation s ability to resist heat flow.

In zone 2 the average minimum requirement for attic insulation is 9 inches of r30 fill. 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. 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. For block walls interior insulation must meet or exceed r 7 8 and exterior insulation must be r 6. 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.

Add the right kind of insulation. In general to optimally isolate an attic on average an r value of the insulation is required ranging from r 50 to r 60. 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 average recommended level is 17 inches of r60.

The higher the r value the better the thermal performance of the insulation. Insulation level are specified by r value. The table below shows what levels of insulation are cost effective for different climates and. Maximum 20 of conditioned floor area.

Recommended home insulation r values. Insulation levels are specified by r value. The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type. Raised r 13 sog r 0 windows.

How much insulation in attic for zones 1 4. R value is a measure of insulation s ability to resist heat traveling through it. Prescriptive compliance form 405. You will need a higher r value of insulation if you live in the northeast than if you live in southern california.

Where you live different climates require different insulation r values. The average recommended level is 14 inches of r49. Insulating power or r value is only one factor to consider when building or improving a home to keep it comfortable. Know exactly how much you need with our project calculators.

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.