Volume 4, Issue 7 (July 2007)
Status on Development of Code Requirements for Exterior Stone Cladding
Existing building codes legislated to set minimum standards for construction state dangerously little about stone used to clad buildings. Without standards, failures have proliferated from the use of new materials in unproven applications and familiar materials in new systems. In response, the American National Standards Institute called upon the industry to develop standards that could be adopted into code. Past reliance on judgment without adequate experience must be replaced by uniform standards that include fundamental principles for the design and installation of contemporary systems to protect the public. To improve responsible use of stone as cladding, building codes must address differences from other veneers. Masonry veneers are more homogenous in production, erection, and behavior than stone, yet stone is presently governed by the same provisions of the building code. The in-progress Code Requirements will include parts of the present ASTM C1242 Standard Guide for Design and ASTM C1528 Standard Guide for Selection. The contents will address minimum material properties by stone type, engineering evaluation, attachment types, safety factors, joint design, and weather barrier integration. This is the status of the document’s development, which upon completion, is intended to be incorporated into the building code. ASTM Committee C18 on Dimension Stone has compiled the industry practice on behalf of producers, engineers, architects, contractors, and owners for over 80 years. While its standard test methods, material specifications, and guides are invoked by many projects’ construction documents, the documented knowledge is not currently incorporated into any of the model building codes, including the International Building Code. To develop the new standard Code Requirements for ANSI, professionals representing all interests of the stone building process are compiling the fundamental aspects of recommended stone cladding practice that should be mandatory.