Rigid Foam Insulation Board R Value
Polyisocyanurate foam board 1 inch thick.
Rigid foam insulation board r value. 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. It s made of environmentally sound closed cell polyisocyanurate foam bonded to a durable white matte non glare aluminum facer and a reflective reinforced aluminum facer. 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.
Extruded polystyrene foam board 1 inch thick 5. Rmax r matte plus 3 1 2 in. This product typically has an r value of 3 6 to 4 0 per inch of thickness. 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. That said the long term r values of this foam board decline over time. Rigid insulation is usually made up of fibrous materials or plastic foams. In severe cold xps panels do see an increase to their r values.
Expanded polystyrene foam board 1 inch thick 3 8 4 4. For example after just 5 years an xps board will see its r value fall by 10 and even more going forward.