R30 Roof Insulation Thickness

Drill holes in the sheathing and blow insulation into the empty wall.

R30 roof insulation thickness.

Eight inches of poor quality insulation may have a higher and better r value than one inch of top quality insulation. This is a significant difference and thus why r 49 batt insulation is used typically in colder climates. Insulation thickness to reach the r 30 value depends on the insulation material but fiberglass batts of r 30 insulation are 9 1 2 inches thick. Rated r value and thickness of insulation r value r6 r11.

Fiberglass panels and rolls with an r 30 insulation value have a typical thickness of eight to nine and a half inches. Professional should specify insulation thickness based r value on the 6 0 r inch design guideline associated with the old lttr test method. R 30 insulation thickness or even r 19 thickness is often used in warmer climates. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.

Note that r30 batt insulation thickness is just 9 1 2 inches thick where as r 49 batt insulation thickness is 15 1 2 inches. 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. Rigid foam insulation provides the same r factor with approximately one half the thickness. As a foil faced polyisocyanurate foam insulation enerfoil tm s r value actually more than doubles.

Wall insulation whenever exterior siding is removed on an. The thickness of r 30 insulation varies depending on the type of insulation used. So you need to know an insulation product s thickness as well as its r value in order to compare it to another product. Find your zone on the map and then use the chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces.