Exterior Wall Insulation R Value

Recommended home insulation r values.

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. The table below shows what levels of insulation are cost effective for different climates and. Higher r value numbers mean that the insulating material resists the cold or heat from the outside better. Insulation level are specified by r value.

Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system. R value is a measure of insulation s ability to resist heat traveling through it. 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. The r refers to absolute thermal resistance.

The higher the r value the better the thermal performance of the insulation. Insulation rolls rolled insulation is another type of insulation blanket similar to batt insulation. R value is a standard unit of measurement for determining among many things how effective your insulation will be. It provides about r 5 per inch.

An r value tells you how well a type of insulation can keep heat from leaving or entering your home. While wall insulation is limited by the width of the studs different materials provide higher or lower r values. 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. Choose this option for areas that need a good amount of strength and water resistance.

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. 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. 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. Basics of faced fiberglass insulation from r 13 to r 19.

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. See the department of energy s doe ranges for recommended levels of insulation below. Typically a higher insulation r rating means better climate control and better energy efficiency for your home. Insulation ratings are measured in r values per inch of thickness.

Try the r value calculator available through oak ridge. Some products have reinforced facing to make them sturdier. Thickness density and type of materials are some factors that contribute to r value. Insulation r values vary based on the type thickness and density of the insulation material.