What Is a Fiberglass & Styrofoam Exterior Wall?

Foam Problems Outside

• Insulating foams, including those made from styrofoam-like products, do not do well in outdoor weather. The moisture, sunlight and changes in temperature tend to quickly damage foam until it wears away. This is why foam insulation in general, and any type of styrofoam board, is not installed directly on an outside wall. They need some type of protection, which is where fiberglass comes in handy.

Fiberglass Board

• Fiberglass is a mixture of matting and plastic resin material designed to offer weather protection for a variety of surfaces. This provides an ideal solution for styrofoam insulation that would otherwise suffer. The foam insulation is installed, and then fiberglass boards are attached over the foam, creating the exterior wall. The fiberglass is not true siding and is not suitable for all buildings, but for basic and inexpensive outdoor coverings the combination can be effective.

Combination Boards

• Because fiberglass can provide protection and works so well with foam insulation, some products are available that combine the two. These combination boards are made with a fiberglass surface for protection and an inner foam layer for greater insulating properties. It can be installed more quickly than trying to use foam and fiberglass materials separately.

Outer Surfaces

• If you want to install siding on your exterior wall, there are siding alternatives that are made from fiberglass. However, these do not include foam insulation. Insulating materials, like thin foam board, need to be installed behind the siding before the fiberglass "boards" are nailed in place. This helps provide necessary insulation and protection from moisture damage.