We offer Dow Thermax (polyisocyanurate) and Dow Styrofoam (XPS, extruded polystyrene) known as Blue Board. Both are closed cell foam products. Rigid insulation comes in panels of various thickness which provide different R values. Easy to work with, rigid insulation can be incorporated into construction or added later to increase R value. Panels are glued or attached with fasteners and can be cut with a utility knife or saw.
Dow Thermax offers increased thermal efficiency and is formulated to provide a class A fire rating. This allows it to be used without an additional covering in interior spaces.
Dow Blue Board is an economic choice that can be used in both interior and exterior applications. Lightweight and easy to use, Dow Styrofoam should be covered by siding, drywall or other materials.
What is "Closed Cell Foam"? Closed Cell Foam is where the cells (bubbles) within the foam are completely enclosed and separated from each other. These closed cells do not allow moisture or air to flow from one cell to another. That's why closed cell foam is a good insulator. Open Cell Foam has openings between cells which allow air and moisture to flow through the foam. A good example of open cell foam is a sponge. Good for collecting water but not a good insulator.
Why use Closed Cell Foam? Aside from being a good insulator, closed cell foam products are excellent at sealing gaps and cracks that allow air to sneak past traditional insulation. Closed cell products don't allow water to collect and are recommended where moisture buildup or mold could be a problem.