Standard Exterior Wall Insulation R Value

Recommended home insulation r values.

Standard exterior wall insulation r value.

For example a wall with 3 fiberglass batting r value of 10 8 11 9 may have an overall r value of nearly 14 because of siding sheathing and drywall. For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed in your attic to reach r 30 if you live in zones 2 or 3. Insulation level are specified by r value. In simple terms r values measure the effectiveness of insulation and a higher number represents more effective insulation.

Because insulation fits the width and depth of the cavity between studs when you compress insulation to fit the space you remove its. Insulation rolls rolled insulation is another type of insulation blanket similar to batt insulation. Note from this. 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.

R value is a standard unit of measurement for determining among many things how effective your insulation will be. For instance if you have a material with an r value of 12 attached to another material with an r value of 3 then both materials combined have an r value of 15. Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system. Higher r value numbers mean that the insulating material resists the cold or heat from the outside better.

The r refers to absolute thermal resistance. Try the r value calculator available through oak ridge. Fiberglass vats are the standard insulator for 2 inch by 4 inch wall framing and are rated r 11 through r 15. The table below shows what levels of insulation are cost effective for different climates and.

Thickness density and type of materials are some factors that contribute to. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. Standard fiberglass batts have r values ranging from r 2 9 to r 3 8 for every inch of thickness but high density insulation batts can have r values as high as r 4 3 per inch. The higher the r value the better the thermal performance of the 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. In order to achieve the higher insulation r value of r 21 a different type of. Fiberglass batts for standard 2 4 walls are now available in low medium and high density products that range from r 11 to r 15.