# Admirable Insulation R Value For Walls

**Installed faced fiberglass batt insulation with its r value visible r 21 in the context of building and construction the r value is a measure of how well a two dimensional barrier such as a layer of insulation a window or a complete wall or ceiling resists the conductive flow of heat.**

**Insulation r value for walls**. R value is a measure of insulation s ability to resist heat traveling through it. The table below shows what levels of insulation are cost effective for different climates and locations in the home. 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. Higher r value numbers mean that the insulating material resists the cold or heat from the outside better.

Thickness density and type of materials are some factors that contribute to r value. See the department of energy s doe ranges for recommended levels of insulation. For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed in your attic to reach r 30 if you. Sprayed foam insulation in the same wall cavity can range from an r 14 to an r 28 depending on the product that is used.

As a benchmark one inch of solid wood has an r value of 1. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. 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. In construction the r value is the measurement of a material s capacity to resist heat flow from one side to the other.

The higher the r value the better the thermal performance of the insulation. The r refers to absolute thermal resistance. 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. 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.

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. 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. In simple terms r values measure the effectiveness of insulation and a higher number represents more effective insulation. 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.

Recommended insulation levels for retrofitting existing wood framed buildings. R value is a standard unit of measurement for determining among many things how effective your insulation will be. 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.