Two updated American Wood Council (AWC) standards have been approved as American National Standards by the American National Standards Institute (ANSI).
The 2015 National Design Specification for Wood Construction (NDS) and Special Design Provisions for Wind and Seismic (SDPWS) standards are referenced for compliance with the International Code Council’s (ICC’s) upcoming 2015 International Building Code (IBC). Pending approval by the authority having jurisdiction (AHJ), AWC is urging designers to use the new standards—many code officials will allow the use of new standards, particularly when they are developed through a consensus process.
“Through their reference in the International Building Code, these standards will allow traditional and engineered wood products to be more easily used in the United States,” said Robert Glowinski, AWC president/CEO. “Our work does not end with these revisions, however. We will now be developing supporting publications such as commentaries, revising technical reports and design aids, and conducting further research to ensure continued widespread acceptance of wood in construction.”
For NDS, a new chapter for cross-laminated timber (CLT) includes the design of members, connections, and fire design. Another significant change is new provisions explicitly permitting structural composite lumber (SCL) to be designed for fire requirements using NDS Chapter 16. The accompanying 2015 NDS Supplement contains updated design values for visually graded southern pine and mixed southern pine dimension lumber.
The 2015 SDPWS contains new provisions for seismic and wind design of cantilevered wood-frame diaphragms that provide important design clarifications, especially for design of ‘corridor-only’ multi-story structures. There are also revisions to the protocol for determining equivalent deformation-based shear distributions that allow more efficient seismic design of shear walls containing high aspect ratio shear walls.
The standards will be available in electronic format on the AWC website by December 1, with print versions expected to be available in early 2015.
These sorts of standardizations will be helpful in the long run, but the adjustment period will be difficult for some.