1 September 1999
WOOD STRUCTURE DESIGN REQUIREMENTS
11-1. INTRODUCTION. This chapter provides a list of guidance documents to be used for the
design of wood buildings. Properties of wood and other considerations influencing design
including design of plywood elements and built-up members, wood preservation, termite
control, fire retardant treatment, and climatic influences are included either in this chapter or in
the referenced guidance documents in Appendix A. Guidance documents referenced include
design standards and specifications. The use of timber construction will consider the type of
occupancy and meet all fire protection criteria and requirements. Detailed design information
on wood buildings is not provided because wood construction is generally limited to residential
construction since strict fire protection standards preclude the use of wood construction for
most other types of military buildings.
11-2. BASIS FOR DESIGN. The design of structural elements or systems constructed
partially or wholly of wood or wood-based products will be by allowable stress design or load
and resistance factor design. The structural analysis and construction of wood elements and
structures using allowable stress design methods will be in accordance with the applicable
standards indicated by reference in Appendix A. The structural analysis and construction of
wood elements and structures using load and resistance factor design methods will be in
accordance with AF&PA/ASCE 16, " Standard for Load and Resistance Factor Design (LRFD)
for Engineered Wood Construction." The design and construction of wood structures to resist
seismic forces and the material used therein will comply with the requirements of TI 809-04,
"Seismic Design for Buildings," and FEMA 302, "NEHRP Recommended Provisions for
Seismic Regulations for New Buildings and Other Structures."
11-3. SERVICEABILITY CONSIDERATIONS.
a. Climatic Considerations. Engineering properties usually are not appreciably affected
when wood is subjected to extremely low temperatures. For cold region limitations on wood
construction, see TM 5-852-9/AFR 88-19, Volume IX. The engineering properties of wood are
not appreciably affected in tropical climates. Rot and insect attacks, however, are aggravated
in tropical humid areas, and all timber for permanent construction in tropical areas should be
tropical climates, structural bonding of wood to other materials should be by means of epoxy
b. Fire Retardant Treatment. Recommendations regarding the use of fire retardant
treatments are provided in the USDA Wood Handbook and the National Fire Protection
Handbook. Pressure impregnation is the preferred treatment method.