Pink and blue rigid foam insulation boards are made from polystyrene resin that is melted and then forced through a die to form it into the desired shape. As insulators, pink and blue boards perform virtually identically, with an insulating value of R-5 per inch of thickness. The two colors of board are sold under different brand names, however, and the two brands are differentiated mainly by the specialized variants within their product lines.
Both pink and blue foam boards are rigid insulation panels made from extruded polystyrene. The chemical composition, manufacturing process and insulating capability of the two products are similar; the principal difference between them is that they are manufactured by two different companies. Pink foam board is manufactured by Owens Corning, and it's marketed under several different brand-specific product names, including Foamular, Propink, Thermapink, and Insulpink. Blue foam board is manufactured by Dow Chemical Co., and it's marketed under the Styrofoam brand name.
Blue Foam Products
Blue foam products intended to be used as sheathing on exterior walls are faced with thin plastic films that protect the board's extruded polystyrene core and add extra strength to the board. Boards intended for interior walls are unfaced, but some of them include convenience features such as notches at the edges to accommodate wood nailing strips. Other blue foam products are designed for roofing or cavity wall applications. High-density blue foam products are designed to resist compression under heavy loads when they're used beneath concrete slabs.
Pink Foam Products
As with blue foam products, varieties of pink foam board are available for a range of specific applications, including interior and exterior wall sheathing, roofing, under-slab insulation and foundation wall insulation. Unique specialized pink foam products include a below-grade foundation insulation board with drainage channels on the surface of the board and a filtration fabric facing that prevents soil from clogging the channels. Owens Corning also offers a pink foam product manufactured with precise thickness tolerances for applications in which a tight connection between the board and an adjacent surface is necessary.
Other Foam Board Types
Pink and blue extruded polystyrene boards are different from expanded polystyrene board. Expanded polystyrene insulation is less expensive than extruded polystyrene, but it is also more fragile and is a less effective insulator. Polyisocyanurate panels, also called ISO panels, consist of a rigid foam core sandwiched between foil or fiberglass facings. ISO panels are strong and insulate more effectively than pink or blue panels, but ISO is significantly more expensive than extruded polystyrene.