Rain Screen Walls A Growing Market – A Growing Opportunity
JOURNAL: ISSUE 3 - 2015
New construction in urban markets, universities, and corporate campuses shows a tremendous growth market in rain screen walls. In many cases these newer systems are used where architects previously preferred curtain wall or metal panels, opening up a growing market for the BAC in rain screen construction.
Says BAC Executive Vice President Tim Driscoll, “The development of rain screen wall systems is the latest chapter in the evolution of building façades. As this technology progresses, the masonry industry must be prepared to address the challenges and opportunities these systems present. BAC and IMI are at the forefront of this effort to ensure that our members and contractors are the most productive and effective resource for masonry rain screen projects.”
Often known for using innovative engineering technology and regional materials in his building designs, Jim Shields, Design Principal of HGA Architects & Engineers and Associate Professor of Architecture at University of Wisconsin-Milwaukee says “Terra cotta rain screens allow architects to specify one of the most ancient and beautiful materials – fired clay – and detail it in a light, yet durable and weather resistant way.” Adds Shields, “We also understand that the craftworkers of the masonry industry are still there for us to install terra cotta masonry even if it is without mortar. We trust and rely upon the refinement of their understanding and craftsmanship to actually build what we draw.”
Rain screen walls are designed to allow air flow behind the veneer within the cavity. Similar to brick masonry cavity walls with open or vented weep holes at the top and bottom of the cavity, any moisture penetration can both drain and dry with air circulation. A properly designed and built rain screen prevents pressure differentials between the cavity and the exterior air, minimizing moisture penetration.
 RSW FUNCTION |
Typical rain screen walls consist of the following:
- the exterior veneer layer
- an air space
- vertical or horizontal channels to support the dead load of the system
- anchors to both attach the veneer and resist lateral loads
- insulation
- an air and vapor barrier
- an appropriate backup system that transfers loads to the structure
Since all of this work must be carefully coordinated, BAC members not only install the rain screen, but the entire wall system as well.
Local 8 WI member Mark Dunco installs a rain screen panel at Kerry Americas Corporate Headquarters in Beloit, WI.
The rain screen itself can be made of many materials. Terra cotta, calcium silicate, natural stone, glass fiber reinforced concrete (GFRC), and most recently, porcelain panels, are just some of the materials that are specified. IMI and IMTEF work hard to build relationships with manufacturers and suppliers of these products, giving advance notice of upcoming projects and allowing access to development of details and specifications.
IMI technical seminars and webinars on rain screen systems and principles have exposed thousands of architects, engineers and construction managers to rain screens and the skill level of BAC craftworkers. Technical articles reach many more designers.
IMTEF provides a craftworker upgrade program in rain screen installation that includes both technical lecture and a hands on component to gain familiarity with the principles and installation techniques of rain screen systems.
BAC contractors are a critical part of the success in gaining this new work. IMI teaches a Rain Screen Estimating course in person and through webinars. In many cases contractors have used mockups at training centers to gain a comfort level with this work prior to bidding.
When architects are confident that they have access to trained craftworkers, they often make it a requirement for bidders.
A recent project in New Jersey contained the following specification language requiring contractors to employ BAC members trained in the specific system:
"1.7 QUALITY ASSURANCE
B. Installer Qualifications:
An employer of workers trained and approved by the Porcelain Stone Ventilated Facade System manufacturer, having experience in the successful completion of projects employing similar materials, applications and performance requirements as specified for this Project or an employer having completed the International Masonry Institute’s - IMI VENTILATED FACADE SYSTEM Course and provided they complete the additional IMI module on the Crossville-Shackerley system prior to construction
Project Example
The Cleveland State University Center for Innovation in Health Professions utilized a terra cotta rain screen system on a new project. Designed by architect Pelli Clarke Pelli (New Haven, CT) at an overall project cost of $35 million, the building used 28,000 square feet of terra cotta rain screen.
The terra cotta package was secured by Bob Zavagno, Jr., President of The Cleveland Marble Mosaic Company (CMM). CMM Superintendent and Local 5 OH member Frank Katuscak coordinated the installation that required ten members of Local 5 to install the mineral wool insulation, the metal channels and rails (the support system for the terra cotta), and the terra cotta units themselves.