INFORMATION SERIES: Exterior Insulation Finish System

retardant features of some of the EIFS components, any water that infiltrates past the surface may become entrapped and eventually cause decay of all adjacent wood components.

While there have been some reports of EIFS problems elsewhere, the initial discovery of this significant concern was in the southeast coastal areas of the United States. The focus

of the initial investigations of it has been in the same area, but, in general, houses in warm, wet areas appear to be most susceptible.

Significant structural damage can occur with repeated episodes of leakage or when the wood reaches high moisture levels. In addition, condensation build-up caused by
missing or improperly installed impermeable interior vapor retarders can add to the moisture entrapment conditions. Unfortunately, these detrimental moisture conditions may go unnoticed unless invasive evaluations are performed or until extensive damage becomes apparent. If your home appears to have this type material, the HouseMaster technical staff recommends an inspection of all exterior walls and surfaces, particularly at the. windows, doors and other openings, for any evidence of inadequately sealed joints and/or signs of moisture infiltration or entrapment.

Though many houses will not outwardly exhibit evidence of the moisture infiltration or subsequent damage associated with EIFS. it still would be prudent for a homeowner to have the house professionally checked by the product manufacturer, and/or a qualified building specialist. In the majority of cases, detrimental conditions may only be detected after removal of some of the siding material. Buyers of homes with this type wall cladding system are also advised to arrange for a professional assessment of conditions, prior to
closing.

Even if there is no evidence of moisture infiltration problems, a house with EIFS will require periodic maintenance to minimize the chance of a future problem developing and to maintain product appearance. All caulking should be checked regularly, and should be replaced or upgraded as conditions dictate.

The finish itself, while not normally needing paint, should be cleaned periodically to prevent staining. Power washing is a common cleaning method, however, care must be taken to ensure that only low pressure systems are used. High pressure power washing is more likely to damage the caulk or other components and allow water to infiltrate behind the surface.

Lawn sprinkler and roof drainage systems should be checked periodically to make sure that they do not direct any water onto the walls or trimwork. Shrubs should also be regularly trimmed to minimize the chance of moisture entrapment against the house.

Note: EIFS is often referred to as "synthetic stucco", but similar synthetic finish coatings are also used in other wall covering applications. The concerns discussed herein relate
only to the application of the full EIFS. Other applications with synthetic stucco coatings, such as those installed over concrete block, are not subject to the same specific concerns; although the trim to coating interface is an area that must be addressed with all exterior finishes or cladding.

The benefits of the EIFS product include design flexibility, variety in color and texture patterns, energy efficiency, and quick installation. The finish coating is also more flexible than conventional stucco, a sand and cement mixture, and consequently less prone to cracking. Other purported features of the EIFS are durability and weather tightness. Over the last few years, however, the validity of these claimed features has been questioned as numerous cases of moisture related problems have been identified in houses constructed with this material. But, as is the case in many similar product reliability situations, there has been some initial controversy as to whether the moisture concerns are primarily due to material, design or installation deficiencies, or a combination of factors.

Specifically identified as a serious concern is the possibility of structural damage to wood sheathing and wall framing, particularly in the areas under and adjacent to windows. The primary cause for this condition appears to be infiltration through improperly sealed joints at the siding and trim work interface. As a result of the moisture 

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