Reflective Attic Insulation R Value

An r value is a measure of an insulation product s resistance to thermal heat transfer.

Reflective attic insulation r value.

Air space equals r value. When determining how much insulation you need don t guesstimate calculate. Because of the presence of the small insulating layer a reflective insulation product by itself achieves a small r value typically around 1 0. For example insulation that is compressed will not provide its full rated r value.

R values for reflective insulations are dependent. If you don t provide air space this product provides almost no insulating 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. It s a measure of how long it takes a heat absorbing product to absorb 100 of its potential and begin to transfer that heat out the other side of the product.

The higher the r value the more resistant a material or building assemblage is to conductive heat transfer. Most people are familiar with the term r value when discussing insulation properties. The rubber meets the road on reflectix s website where it says no air space no reflective insulation benefit. The higher the r value the greater the insulation performance.

What about r values for a reflective insulation and why do they vary with application. Reflectix can provide verification for all r values stated for all products and applications. A reflective insulation product is a thicker product with an insulating middle layer such as fiberglass foam or air bubbles.