A Stucco Inspection is designed to ensure proper insulation of a home’s exterior. Synthetic stucco is an exterior wall siding commonly known as an exterior insulation finish system (EIFS), and consists of four main components:
- Foam insulation boards attached to the exterior wall sheathing
- A base coat applied to the insulation board
- A fiberglass reinforcing mesh embedded in the base coat
- A finish coat applied over the fiberglass mesh
The exterior insulation finish system (EIFS) may resemble stucco in appearance, however the two siding systems are actually very different, especially when it comes to controlling water intrusion. The traditional stucco system is designed to anticipate potential water penetration through open joints and cracks. In order to prevent rot and deterioration of the wood framing and sheathing in the exterior walls, stucco uses a housewrap or building paper behind the stucco surface to carry any water that accumulates in that area down and out the bottom of the wall.
Meanwhile, the EIFS was not designed for water intrusion. Because it resisted water penetration at its outer surface it was considered a surface barrier system, assuming moisture would not penetrate the surface and reach the wall sheathing and/or framing. This system, however, was not originally intended to drain water that reached behind the EIFS cladding.
Leaving the theory aside, water did in fact penetrate the wall, not through the surface but through jambs and sills of window frames, as well as at the joints between the exterior walls and door, window, deck and roof intersections. Because this system was not designed to drain water, the water that penetrated the wall became trapped between the EIFS cladding and the sheathing.
The water was absorbed by the sheathing and framing, both of which increased their moisture content to a level above saturation, resulting in rot and structural damage. Significant damage caused by moisture could occur, depending also on weather conditions and the quality of construction. Inspections revealed damage from water intrusion in the exterior walls of houses that are only three to five years old.
Stucco Inspection – New vs. Old EIFS
Acknowledging the problems that stemmed from the lack of drainage in the wall, the industry modified the system to include the installation of drainage channels and building paper or housewrap between the foam insulation and the sheathing. The new system is very similar in appearance to the old EIFS, and a visual inspection could not determine whether it is drainable or nondrainable EIFS.
The point of water entry is often difficult to see and locate, and moisture damage to the sheathing and framing behind the exterior wall cladding cannot be readily detected by visual inspection.
If you have an EIFS exterior wall cladding, perform a preliminary inspection by checking for any cracked and open joints at the interfaces between the EIFS and different materials such as windows and doors. If you find any areas that require caulking, record it on your worksheet for later correction. In addition, those areas should also be checked for water intrusion. To do this, use a non-invasive moisture meter.
On the other hand, given the nature of the potential problems and the costly corrective measures that would be required, it would be best to hire a professional to inspect and evaluate the exterior walls.