What is Stucco? Hybrid Stucco

Advisory Report - June 2003

What is Stucco? 
Part Three of Three: Hybrid Stucco

In this final article, we will discuss how U.S. Inspect classifies Hybrid stucco. 

U.S. Inspect defines Hybrid stucco as a system that falls outside the design and components of the following standard systems: Conventional or EIFS Class-PB (barrier EIFS). Though a manufacturer may produce a system that has a set specification (such as EIFS Class-PM, FRP, Direct applied or One-Coat), known data, testing and litigation information is not available for Hybrid Systems.

U.S. Inspect groups these non-standard systems in the class of hybrid to limit the amount of confusion that can occur when systems are named. Also, due to the similarities of some systems, they truly cannot be determined without a sample of the product being laboratory-analyzed to determine the proprietary mixture of the base and finish coat.

Known Problems with Hybrid Stucco
Problems exist with all exterior cladding; brick, any type of siding material (aluminum, wood, composite), stone and others. To say that only EIFS Class-PB (barrier EIFS) stucco systems are singular in having problems is incorrect. The fact that litigation has entered into the equation is the deciding factor. EIFS Class-PB has inherent design and installation flaws that can create undue damage to a home. This is similar to the litigation that came about surrounding composition board siding (Louisiana Pacific, Georgia Pacific and Masonite). 

Hybrid stucco systems have the same problems that any other exterior claddings are prone to producing. Improper installation methods (non-adherence to specifications, shoddy workmanship, mixing materials from various manufacturers, etc.) can cause a number of problems, which may not manifest themselves for many years. One common concern with Hybrid systems is the typical presence of foam-insulating products. Foam is a red flag for many people because it is one of the key components of the controversial Class PB EIFS system. However, there is very little known data to support, whether foam is a factor in problems with Hybrid stucco. 

Synthetic Finish Coat vs. Synthetic Stucco
A synthetic finish coat is a common application in modern building techniques for stucco. It provides a flexible outer layer that will provide additional support and protection to the base layers, as well as aesthetic value. Conventional stucco systems are increasingly having a synthetic finish coat added. 

Most Hybrid stucco systems are synthetic based and have foam as a component, though cases do exist (as in Texas and Georgia) where foam is placed behind an otherwise conventional stucco system. System thickness, type of lath and or mesh and foam type are factors in determining the type of system. The acronym “EIFS” has become a “red-flag” in the industry, and should only pertain to Class-PB systems; not Conventional or Hybrid.

The primary concern in the EIFS issue is with the Class-PB System, as defined in the class-action litigation. In fact, many of the Hybrid systems have been produced as either a supplement or for the purpose of supplanting Class-PB systems. One such system is the Drainable or Water Managed System. This is a stucco system with channeled foam and/or moisture mat, and a weather barrier installed. These Hybrid systems are so new that no definitive information has yet been developed as to the feasibility or inherent problems in these systems. 

Conclusion
The stigma associated with the acronym “EIFS” and the word “synthetic” have raised concerns with real estate professionals and homeowners alike. Problems exist with all exterior cladding systems, through various reasons, and should be considered accordingly in the risk assessment process.

Click here to watch a 13-minute video documentary about EIFS.

Click here for more information about EIFS and other stucco systems.

Click here to read our previous discussion of Conventional Stucco, posted in April 2003, and here to read our previous discussion of Synthetic Stucco, posted in May 2003.

Contributed by Kyle Bost
Senior Technical Advisor
U.S. Inspect, LLC