Minimizing Liability

Traditional flashing systems depend on proper materials, details, specifications, installation conditions, and workmanship. Failure of any of these elements to perform increases the potential for building envelope moisture intrusion, which can lead to leaks, mold, and potential lawsuits.

Use of a liquid applied flashing system eliminates many of the variables that can lead to failure in traditional flashing systems, thereby minimizing liability and risk. This flashing system works well with overall building performance criteria to keep moisture out of walls and interior areas.

According to Tian Feng, AIA, FCSI, Chief Architect, San Francisco Bay Area Rapid Transit, and former construction expert witness consultant, Oakland, California, architects who fail to provide appropriate specifications and flashing details can pay a high price in court. "When I was a construction expert witness, nearly all building failure cases were related to water or moisture intrusion from building envelopes, and over half of those cases were due to flashing failures. While common perceptions attribute failure to workmanship, the reality has been contrary. Successful flashing relies upon more than good workmanship in installation; it begins early on in product selection and specifications.

"The best practice is to define the water and moisture resisting performance criteria, followed by working with manufacturers and installers to determine the appropriate system, instead of reusing old, often outdated, office master specifications and details. I saw too many flawed "cut and paste" specifications and details that rarely held up in court to the experts during litigation. Every one of these "cut and paste" specifications proved to be costly for the design firms and their insurance companies," Feng observes.

Summary

Successful building envelope design requires more than aesthetic qualities on the outside. Keeping water out, heat or cooled air in, and resisting the impact of wind, blast, heat gain, and seismic forces have become among the many challenges facing architects, design professionals and owners. Many of the most important building envelope design elements, such as performance criteria and building system components, are hidden from view. In an increasingly risk-prone environment, and litigious society, design professionals must have a broad understanding of the many factors that contribute to building envelope design and construction.

As this roundup of innovative products, concepts, and trends has demonstrated, architects have many options when reviewing building envelope products, related components, and systems. Increasingly, these new products and systems offer various features that are designed to enhance performance and potentially reduce risk to architects and owners. Installation, warranties, the nature of the labor force, and product delivery schedules are other considerations that can streamline, or complicate, project schedules and budgets.

As far as building envelope trends, sustainability, moisture intrusion, energy efficiency, solar control, enhanced use of glass, new technology, along with high performance composite materials, products, and systems, are likely to remain important product concepts in the building envelope marketplace. If the present is any indication, these products will be constantly changing and updated, to meet the next challenge, capture the next trend, and provide architects with even more exciting design opportunities.

Barbara A. Nadel, FAIA, principal of Barbara Nadel Architect, in New York City, frequently writes about design and technology. She is the author and editor-in-chief of Building Security: Handbook for Architectural Planning and Design (McGraw-Hill, 2004).