Exterior Wall Insulation R Value

Exterior walls if your exterior walls are constructed from 2 by 4 inch studs the most insulation that can go into the wall while retaining its r value is r 13 or r 15 as these are both made to fit a cavity 3 1 2 inches deep.

Exterior wall insulation r value.

The r refers to absolute thermal resistance. 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. Insulation level are specified by r value. Recommended home insulation r values.

Basics of faced fiberglass insulation from r 13 to r 19. Insulation rolls rolled insulation is another type of insulation blanket similar to batt insulation. Some products have reinforced facing to make them sturdier. R value is a measure of insulation s ability to resist heat traveling through it.

The higher the r value the better the thermal performance of the insulation. 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. 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. It provides r values that range from 3 6 to 4 2 per inch.

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. Insulation r values vary based on the type thickness and density of the insulation material. This material offers the highest r values about r 6 to 6 5. It provides about r 5 per inch.

Try the r value calculator available through oak ridge. The table below shows what levels of insulation are cost effective for different climates and. 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. 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.

Thickness density and type of materials are some factors that contribute to r value. An r value tells you how well a type of insulation can keep heat from leaving or entering your home. Choose this option for areas that need a good amount of strength and water resistance. Insulation ratings are measured in r values per inch of thickness.

R value is a standard unit of measurement for determining among many things how effective your insulation will be. While wall insulation is limited by the width of the studs different materials provide higher or lower r values. 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.