Rigid foam Wall Insulation

What comes to mind when someone says "insulation?" Most of us think of fiberglass batts, visualizing spun glass fibers that look a lot like cotton candy. Other folks might envision shredded newspaper, the main ingredient in cellulose insulation.

No water damage, no mold, no loss of R-value

Rigid foam insulation hasn't been around as long as fiberglass or cellulose insulation, but it's gaining plenty of fans among builders and homeowners who like its characteristics. It's well-suited for use as wall insulation and other applications.

Although there are different types of rigid foam insulation (see below), all rigid foam insulation has certain noteworthy advantages. For example, fiberglass and cellulose insulation can't stop air movement, but rigid foam can if joints between panels are sealed with special tape. Rigid foam insulation won't absorb water, support mold growth or compress and lose its R-value like fiberglass insulation can.

Ideal Insulation for Masonry Walls

Rigid foam panels come in a variety of thicknesses and widths. 2-ft. x 8-ft. and 4-ft. x 8-ft. panels are most common. The material is lightweight and easy to handle, and it cuts easily with a knife or saw. The most common use is insulating masonry walls. It can be glued to masonry surfaces with an appropriate panel adhesive or secured with masonry fasteners. Either way, it forms a consistent, continuous thermal barrier to make basement and crawl space areas more energy efficient. Building codes usually require the foam to be covered with a fire-rated material in basement applications. Here are the three main types of rigid foam insulation:

• Polyisocyanurate (polyiso for short) foam has the highest R-value per inch (R-6) of any rigid insulation. This material comes with a reflective foil facing on both sides, so it can also serve as a radiant barrier in some applications. Polyiso board is more expensive than other types of rigid foam.
• Extruded polystyrene (XPS) rigid foam is usually blue or pink, with a smooth plastic surface. The R-value is about R-5 per in.
• Expanded polystyrene (EPS) rigid foam is the least-expensive type of rigid foam and has an R-value of around R-3.8 per in. Standard EPS foam panels are white, but the specially made SilverGlo panels available exclusively from Dr. Energy Saver have grey-toned foam and a silver radiant barrier facing. Available in different thicknesses, SilverGlo offers the best value and the most versatility for insulating and air-sealing.

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