EIFS (Exterior Insulated Finish System)

The System and installation:

EIFS is attached to the outside face of exterior walls with a cement or acrylic-based adhesive.
The supporting wall surface is continuous and flat. Common substrates include concrete, block, brick, cement board, exterior grade gypsum glass fiber sheathing (Dens Glass), oriented-strand board (OSB), and wrapped plywood.
The most basic EIFS (a barrier EIFS) consists of 3 layers. EIFS also has a variant with Drainage or water resistive barrier- WRB, a barrier EIFS to which a water drainage capability has been added. EIFS consists of layers that are installed in the following order.

• The first layer is Expanded Polystyrene, also known as EPS, which is adhesive applied to the substrate. The usual range of thickness for EIFS insulation is 3/4″ to 4″ and sheets measures 2’ x 4’, thicker pieces can be used for decoration accents and foam shapes.
• A second reinforced layer is applied onto the face of the insulation with a trowel, consisting of a fiberglass reinforcing mesh embedded in a cement-based adhesive. The mesh has an open weave, somewhat like window screening but with opening about 1/4″ square. The mesh is available in various weights; the “heaviness” determines the impact strength of the surface (resistance to damage by being “hit”). The standard weight is 4oz, the high-impact mesh weight goes up to 20oz. This 2-part layer is called the Base Coat.
• A final acrylic topcoat, or finish, which is a colored, textured paint-like material that is trowel applied. A wide range of colors and textures are available as well as custom colors. Available textures include smooth surfaces, sand finishes or rough “stucco-like” textures, embedded stone chips, multi-color (granite-like mixtures,) and even brick-like treatments. This layer is called the finish. It is acquired by floating.