What Is EIFS Stucco?
EIFS, Exterior Insulation Finish Systems, is a type of exterior wall covering that mimics the look of stucco but adds an element of insulation and weather protection. EIFS can stand alone as a finish, or can be molded to replicate almost any architectural style. It can also adhere to nearly every exterior wall surface. EIFS does, however, require substantially different upkeep and installation from other finishing systems or traditional stucco.
EIFS has been in use since shortly after the Second World War in Europe, where old masonry buildings were in need of further insulation and aesthetic upgrades. In the early 1950s, insulation board and synthetic plaster both became popular and were eventually marketed together in Europe as early as 1963. Shortly thereafter, the technology became available in the United States as a finishing for commercial and, eventually, residential buildings. In the '90s, EIFS became controversial as cases began to surface in which improper installation caused water damage to homes.
The modern version of EIFS consists of three main parts: the insulation board, the base coat and the finishing coat. The insulation board part of the construction is usually made of polystyrene or a similar material and is applied either manually or mechanically to the surface of an exterior wall. This board gives the system excellent energy efficiency, with many users reporting as much as a 55 percent decrease in air infiltration compared with wood and brick walls. The base coat involves a synthetic plaster reinforced with a fiberglass mesh. The final layer is the finish, which is decorative and waterproof and gives EIFS its stucco-like appearance.
The majority of problems that are reported with EIFS involve moisture damage, including mold, rot and decay. These are usually due to improper installation. The problem begins if there is any air pocket at all between the insulation board and the base wall. This is almost inevitable, because creating an airtight system is next to impossible on large walls. This issue becomes dangerous when water penetrates the synthetic plaster on the outer part of the EIFS. At this point, water is allowed to enter the airspace and remains for long periods of time, causing rot and decay. Usually, this is due to improper flashing and caulking during installation or a lack of maintenance on the homeowner's part.
Before beginning installation of EIFS, check the certifications and reputations of the builders you are hiring. Builder-accepted standards for EIFS installation exist, and shortcuts can lead to moisture entrapment years down the road. Often, many problems due to improper EIFS installation can be fixed easily and cheaply if caught early. Therefore, it is advisable to have an inspector check the wall every year to check for damage. Repairs usually involve simple caulking or reflashing. If left unseen, the damage can grow, and repair may involve tearing down and replacing the EIFS, which is much more costly.