Rigid Foam Insulation Board R Value

For example after just 5 years an xps board will see its r value fall by 10 and even more going forward.

Rigid foam insulation board r value.

Expanded polystyrene foam board 1 inch thick 3 8 4 4. The fibrous materials such as wood cane or vegetable fibers are mixed with fillers and binders to form insulation boards. It is offered in multiple thicknesses and dimensions in both square edged and tongue and groove joints. Expanded polystyrene insulation is similar to the foam used for packing peanuts and it s typically used for insulated concrete forms also knows as icf s.

Rigid insulation is usually made up of fibrous materials or plastic foams. That said the long term r values of this foam board decline over time. A popular rigid insulation choice xps features an initial r value of r 5 per inch. Our r value guide to rigid insulation includes the doe s recommended insulation by zone chart r value calculator and base building material r values chart.

Insulfoam rigid foam is a high performance built to spec sheathing insulation that provides superior r value and moisture resistance. In severe cold xps panels do see an increase to their r values. Rmax r matte plus 3 1 2 in. Rigid insulation r value by comparison usually ranges from r 4 0 to 6 5 and may get as high as r 8 7 depending on the insulation material.

This product typically has an r value of 3 6 to 4 0 per inch of thickness. Extruded polystyrene foam board 1 inch thick 5.