Exterior Wall Insulation R Value

It provides r values that range from 3 6 to 4 2 per inch.

Exterior wall insulation r value.

R value is a standard unit of measurement for determining among many things how effective your insulation will be. 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. 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.

Basics of faced fiberglass insulation from r 13 to r 19. 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. 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. Typically a higher insulation r rating means better climate control and better energy efficiency for your home.

Recommended home insulation r values. Higher r value numbers mean that the insulating material resists the cold or heat from the outside better. Insulation r values vary based on the type thickness and density of the insulation material. See the department of energy s doe ranges for recommended levels of insulation below.

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. Insulation level are specified by r value. Choose this option for areas that need a good amount of strength and water resistance. This material offers the highest r values about r 6 to 6 5.

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. 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 rolls rolled insulation is another type of insulation blanket similar to batt insulation. An r value tells you how well a type of insulation can keep heat from leaving or entering your home.

The higher the r value the better the thermal performance of the insulation. R value is a measure of insulation s ability to resist heat traveling through it. Some products have reinforced facing to make them sturdier. While wall insulation is limited by the width of the studs different materials provide higher or lower r values.

The r refers to absolute thermal resistance. Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system. It provides about r 5 per inch. 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.