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Since its founding in 1939, the Steel Deck Institute (SDI) has provided uniform industry standards for the engineering, design, manufacture, and field usage of steel floor and roof decks. Members of the SDI are manufacturers of steel roof and floor decks. The products that they manufacture are primarily used to support overlying roofing materials or to serve as a permanent form and/or positive reinforcement for concrete floor slabs.


At present, the SDI has twenty-four deck producing members and nine associate members. Associate members are manufacturers of products related to the use of steel decks. The member companies operate certified deck manufacturing facilities located throughout the United States. The SDI Board of Directors holds quarterly committee meetings where marketing and technical issues related to steel deck are acted upon.


There are many advantages to using steel deck in roof and floor construction. These include physical properties such as structural strength, all weather constructability, and fire resistance. Uniform quality, proven durability, and economic value have also long been known to be attributes of steel roof and floor deck. More recently, building designers have recognized the advantages of steel deck for its appearance, acoustical properties, and sustainability. The mission of the SDI is to promote these advantages and to provide guidance in the proper usage of steel roof and floor deck.


The SDI is an American National Standards Institute (ANSI) Accredited Standards Developer (ASD). Our design standards are incorporated into the International Building Code (IBC) and the NFPA 5000: Building Construction and Safety Code.


SDI Standards incorporated into the IBC and NFPA 5000 include:

  • ANSI/SDI C-2017 “Standard for Composite Steel Floor Deck-Slabs”
  • ANSI/SDI NC-2017 “Standard for Non-Composite Steel Floor Deck”
  • ANSI/SDI RD-2017 “Standard for Steel Roof Deck”
  • ANSI/SDI QA/QC-2017 “Standard for Quality Control and Quality Assurance for Installation of Steel Deck”


The SDI is also widely known for its design manuals for roof deck (SDI Roof Deck Design Manual), floor deck (SDI Floor Deck Design Manual), and diaphragm design (SDI Diaphragm Design Manual, 4th Edition). Most recently, the SDI has published the Steel Deck on Cold-Formed Steel Framing Design Manual. These publications include load tables for standard profiles and fasteners and many design examples. Other SDI publications include the Manual of Construction with Steel Deck (MOC3), the 2017 SDI Code of Standard Practice (COSP17), and the SDI Standard Practice Details (SPD2). Numerous white papers, position statements, and technical notes have also been published. An Environmental Product Declaration (EPD) for steel roof and floor deck is also now available. All of these documents can be accessed for download and/ or purchase by visiting our website at


In addition to publications, the SDI participates in other outreach and educational activities. The SDI is a regular exhibitor at the AISC North American Steel Construction Conference (NASCC) and the National Council of Structural Engineering Associations (NCSEA) Engineering Summit. In conjunction with the Steel Joist Institute, the SDI presents several webinars each year. Also, SDI staff and membership present papers and seminars at numerous national and regional conferences and technical meetings each year.


The SDI collaborates with other nationally known industry organizations to develop consensus standards, to conduct research projects, and to promote the use of steel in building construction. These include the American Iron and Steel Institute (AISI), the Steel Joist Institute (SJI), the American Institute of Steel Construction (AISC), the American Welding Society (AWS), and the American Society of Civil Engineers (ASCE). Products and assemblies listed and/ or rated by Factory Mutual (FM), Underwriters Laboratories (UL), and various evaluation services are available from most SDI member companies.