External Wall Insulation R Value

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

External wall insulation r value.

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. Let me explain when the general public hears an r 13 wall insulation they believe that in. 1 2 exterior plywood has an r value of 0 63 and exterior wood bevel siding has an r value of just 0 80. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation.

Insulation is rated in two ways r value and u value. But when you add 3 1 2 of fiberglass insulation with an r value of 11 0 the entire wall structure can have a thermal resistance of nearly 14 not bad but not ideal especially in. The higher the r value the better the thermal performance of the insulation. Insulation level are specified by r value.

The r value is a calculation which measures the flow of heat through an insulation product or its. The table below shows what levels of insulation are cost effective for different climates and locations in the home. Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system. 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.

R value is a measure of insulation s ability to resist heat traveling through it. Higher r value numbers mean that the insulating material resists the cold or heat from the outside better. Find your zone on the map and then use the above insulation r value chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces. The r refers to absolute thermal resistance.

Because insulation fits the width and depth of the cavity between studs when you compress insulation to fit the space you remove its. In simple terms r values measure the effectiveness of insulation and a higher number represents more effective insulation. 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. 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.

How to achieve r 21 in a 2x4 wall. Thickness density and type of materials are some factors that contribute to. Try the r value calculator available through oak ridge.