2021 Fire Design Specification for Wood Construction

114 pages (3,019 KB PDF)

This Specification is a pre-standard for use in designing wood buildings. Its use is intended to complement and not supersede any provision of the applicable building code.

Since 2001, the National Design Specification® for Wood Construction (NDS®) has contained provisions in Chapter 16 for design of fire exposed wood members to meet code-required structural fire-resistance ratings based on a standardized ASTM E119 time-temperature exposure. The NDS Chapter 16 provisions apply to exposed timber members of sawn lumber, glued-laminated softwood timber, laminated veneer lumber, parallel strand lumber, laminated strand lumber, and cross-laminated timber. Additional calculation procedures have been developed to address the added fire resistance and thermal benefits of protection using additional wood, gypsum panel products, and some types of insulation. These additional calculation provisions have been developed to provide standardized methods of calculating thermal separation and burn-through requirements as required in ASTM E119 and as provided in AWC’s Technical Report 10: Calculating the Fire Resistance of Exposed and Protected Wood Members (TR10). The existing design provisions in NDS Chapter 16 and the new protection provisions contained within TR10 have been incorporated in this Specification.

In developing the provisions of this Specification, the most reliable data available from laboratory tests and experience with structures in service have been carefully analyzed and evaluated for the purpose of providing, in convenient form, a national standard of practice. AWC invites and welcomes comments, inquiries, suggestions, and new data relative to the provisions of this document.

It is intended that this Specification be used in conjunction with competent engineering design, accurate fabrication, and adequate supervision of construction. AWC does not assume any responsibility for errors or omissions in the document, nor for engineering designs, plans, or construction prepared from it. Those using this standard assume all liability arising from its use. The design of engineered structures is within the scope of expertise of licensed engineers, architects, or other licensed professionals for applications to a particular structure.