An exterior wall covering (cladding) is a non-load-bearing material or assembly that is applied over the exterior walls of a house. Houses built using wood-frame and light-gauge steel construction need a wall covering to shed liquid water.

Wall coverings are often referred to as veneers. There are three categories of veneers. Most wall covering veneers are attached veneers; so called because the veneer is attached to the house with fasteners. All types of siding, and exterior insulation and finish system (EIFS), are attached veneers. Brick and natural stone are anchored veneers. Anchored veneers are supported directly on the foundation, or on reinforced framing, and are anchored to the house walls to prevent the veneer from rotating away from the structure. Stucco and artificial and some natural stone are adhered veneers; so called because the components are attached to the house walls with mortar that acts as a “glue” to adhere the components to the wall.

Houses built using materials such as structural brick and stone, concrete masonry units (concrete blocks), and insulated concrete forms do not need an exterior wall covering. A water-repellant material such as stucco may be applied directly to the exterior walls of the house, or a coat of paint may be applied as a water-repellant material. In these cases, the stucco or paint is a coating, not a wall covering. A wall covering such as brick may be installed as a wall covering over structural materials. Log home exterior walls are usually stained, sealed, or painted and usually do not have a separate wall covering.

Exterior wall coverings serve two functions. Their first function is to shed liquid water and keep it from entering into the home. Their second function is to protect any water-resistive barrier (WRB) that may be present under the wall covering. Of course, exterior wall coverings also serve an important architectural and aesthetic function, but these issues are out of scope of a home inspection.

Exterior wall coverings shed water, but are not water-resistive barriers. It must be assumed that water will get behind wall coverings; therefore, another line of defense is required. This second, and most important, line of defense is the water-resistive barrier, and flashing under the wall covering. When the water-resistive barrier and flashing are properly installed, water that gets behind the wall covering should drain down the water-resistive barrier and out of the weep holes or other openings.

The exterior wall coverings that home inspectors are most likely to encounter are discussed in this section. This is not a discussion of all exterior wall coverings.