Exterior Wall Insulation R Value

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.

Exterior wall insulation r value.

Recommended home insulation r values. 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 table below shows what levels of insulation are cost effective for different climates and. Other typical wall materials have similarly low values.

Thickness density and type of materials are some factors that contribute to. 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. 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 r refers to absolute thermal resistance. 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. 1 2 exterior plywood has an r value of 0 63 and exterior wood bevel siding has an r value of just 0 80. 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.

Higher r value numbers mean that the insulating material resists the cold or heat from the outside better. 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 truth is this studs have an r value of 3 5. Insulation level are specified by r value.

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. 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.