# Insulation R Value For Walls New

**Additional r value for a masonry wall constructed using these materials needs to add the insulating value of additional wall components typically included such as 1 solid foam polyisocyanurate r 8 extruded polystyrene r 5 expanded polystyrene r 4 or 1 of perlite r 2 7 and for an exterior air film winter no wind r 0 17 an interior air film again no air movement r 0 68 3 4 of reflective air space no convective air movement r 2 89 1 2 drywall r 0 45 interior wall.**

**Insulation r value for walls**. Insulation level are specified by r value. The higher the r value the better the thermal performance of the insulation. Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system.

The table below shows what levels of insulation are cost effective for different climates and locations in the home. As a benchmark one inch of solid wood has an r value of 1. 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.

R value is a measure of insulation s ability to resist heat traveling through it. In construction the r value is the measurement of a material s capacity to resist heat flow from one side to the other. 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. Recommended insulation levels for retrofitting existing wood framed buildings. In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and an inch of blown cellulose in an attic has an r value of 3 2 3 7.

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. 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. If we install these same three windows packages to the 2x6 wall blown in with no exterior insulation we find that the whole wall r value ranges from 10 4 to 11 5 to 12 9 respectively.

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. Higher r value numbers mean that the insulating material resists the cold or heat from the outside better. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation.