Exterior Wall Insulation R Value

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.

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. 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. 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. Insulation level are specified by r value. Recommended home insulation r values. An r value tells you how well a type of insulation can keep heat from leaving or entering your home.

Some products have reinforced facing to make them sturdier. Thickness density and type of materials are some factors that contribute to r value. Typically a higher insulation r rating means better climate control and better energy efficiency for your home. Try the r value calculator available through oak ridge.

This material offers the highest r values about r 6 to 6 5. Insulation r values vary based on the type thickness and density of the insulation material. 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. Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system.

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. The r refers to absolute thermal resistance. Choose this option for areas that need a good amount of strength and water resistance. It provides r values that range from 3 6 to 4 2 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. 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. 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. R value is a measure of insulation s ability to resist heat traveling through it. 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. Basics of faced fiberglass insulation from r 13 to r 19.