Outside Wall Insulation R Value

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

Outside wall insulation r value.

Vapour barriers help control the amount of moisture that passes through insulation and are commonly used when framing the exterior walls of a house. Achieving greater r values in exterior walls. The r refers to absolute thermal resistance. If moisture from either direction is allowed to build up within the stud or cavity walls the heat conducting moisture will cause the insulation to lose its r value and allow mould and rot to set.

The higher the r value the better the thermal performance of the insulation. 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. 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. As with attics or anywhere else in your home adding more layers of insulation to your exterior walls is key to having a higher r value and better thermal performance.

Insulation is rated in two ways r value and u value. 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. 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. The truth is this studs have an r value of 3 5.

Insulation level are specified by r value. 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 measure of insulation s ability to resist heat traveling through it. How to achieve r 21 in a 2x4 wall.

The table below shows what levels of insulation are cost effective for different climates and. Thickness density and type of materials are some factors that contribute to. 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. The r value is a calculation which measures the flow of heat through an insulation product or its.

Recommended home insulation r values. You can achieve better thermal performance in your attic by adding an additional layer of insulation. Foam board insulation is easy to install between wall studs and over existing blanket insulation.