Exterior Wall Insulation R Value

R value is a measure of insulation s ability to resist heat traveling through it.

Exterior wall insulation r value.

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. 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. The r refers to absolute thermal resistance.

Recommended home insulation r values. Insulation level are specified by r value. Thickness density and type of materials are some factors that contribute to. In simple terms r values measure the effectiveness of insulation and a higher number represents more effective insulation.

R value is a standard unit of measurement for determining among many things how effective your insulation will be. The higher the r value the better the thermal performance of the insulation. The overall r value of a wall or ceiling will be somewhat different from the r value of the insulation itself because heat flows more readily through studs joists and other building materials in a phenomenon known as thermal bridging. 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.

Other typical wall materials have similarly low values. 1 2 exterior plywood has an r value of 0 63 and exterior wood bevel siding has an r value of just 0 80. Let me explain when the general public hears an r 13 wall insulation they believe that in fact they have an r 13 insulation value in their exterior walls. 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.

These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. The net effect on the r value of the wall with the studs transferring heat cold thru conductive properties is the actual rating of that.