The Cast Stone Institute is aware that this product is in the market and identifying as cast stone. It is a scratch coat of concrete or resin material over foam to form a lightweight unit. This is NOT cast stone and therefore can NOT be specified under ASTM C1364 Standard for Architectural Cast Stone or by Construction Specifiers Institute Specification 047200. There are no standards in place for this product and it is not a part of the Cast Stone Institute Certification. Any performance characteristics indicated in marketing of this product as relates to ASTM C1364 are false. If you wish to have additional information, contact the CSI office. NOTE: A new MasterFormat  # 04 73 23 Lightweight Synthetic Stone -- was announced for this product in June 2020. For more information on this, contact Construction Specifications Institute

Welcome to the Cast Stone Institute®
The Cast Stone Institute® (CSI) was formed in 1927 by a group of visionary Cast Stone producers who identified the need to have a common voice for the Cast Stone industry. Today our mission remains, not only to be the authoritative spokesperson for Cast Stone, but also to provide expert counsel to the architectural and engineering communities.

Members of the Cast Stone Institute® are engaged in the relentless pursuit of excellence in manufacturing. Prior to admission, each potential CSI producer member must submit to a rigorous examination of product quality, safety, testing and meticulous record keeping. Cast Stone Institute® producer members must also undergo the recertification process every two years. The results of this self-governing association of producers include consistently high product quality, through continuous improvement in manufacturing methods and materials, and the assurance that Cast Stone Institute members are “on the job” keeping Cast Stone a premier building material. The Cast Stone Institute, through its standing committees disseminates current information and standards regarding the design, manufacturing, installation and use of Cast Stone.

As of January 1, 2011, all Certified Cast Stone Institute Producing Members provide a 10-year Limited Product Warranty for the Cast Stone they supply on projects. This warranty demonstrates that CSI Producer Members embrace sustainability, durability, and produce product that will stand the test of time.

All Cast Stone Institute Producer Members are required to supply product that complies with ASTM C1364. Not all of the Cast Stone industry necessarily complies with all of the requirements of ASTM C1364 (which includes a freeze thaw component).

Cast Stone is a masonry product that provides ornamental or functional features to buildings and other structures. Cast Stone products are available in virtually any color, and will give the appearance of a variety of natural building stones including but not limited to limestone, granite, slate, travertine or marble. Properly manufactured, Cast Stone has the same or stronger physical properties as most dimensional building stone.

Care and installation of Cast Stone are referenced in many of the Cast Stone Institute® publications and technical bulletins available for free download under Technical Resources. CSI producer members also stand ready to provide experienced and reliable counsel. Please consult the membership directory of this website for CSI Certified Cast Stone producers.

Cast Stone Institute® educational efforts include presentations to general contractors, masonry contractors, non-AIA architects and structural engineers. To take advantage of educational or informational opportunities, please contact the Cast Stone Institute® office.

CSI AECDAILY Continuing Education American Institute of Architects Website