In the 2001 and 2005 National Design Specification^® (NDS^®) for Wood Construction, calculation of reference lateral design values for lag screws and wood screws will typically require use of the fastener root diameter, D_r, unless a more detailed analysis is performed to account for the varying moment and bearing resistance of the fastener (NDS Section 11.3.2). One alternate method of accounting for the moment and bearing resistance of the threaded portion of the fastener and moment acting along the length of the fastener is provided in AF&PA’s Technical Report 12 (TR12) - General Dowel Equations for Calculating Lateral Connection Values.

Example calculations in this Design Aid are shown for lag screw connections; however, the design approach is also valid for wood screws. Example 1 addresses application of TR12 for three lag screw connections having identical side and main members but different screw geometry. Example 2 addresses calculation for the required length of unthreaded shank into the main member such that diameter, D, is applicable for calculation of reference lateral design values.

This Design Aid was developed as supplemental information for the National Design Specification^® (NDS^®) for Wood Construction to facilitate the design of connections. These tables are based on provisions of the 2001 and later editions of the NDS which are integral to the use and understanding of the tables.

Reference design values for post frame ring shank nails in accordance with ASTM F1667 are provided in DA4: Post Frame Ring Shank Nails. Tabulated values are calculated in accordance with the 2005 National Design Specification^® (NDS^®) for Wood Construction yield limit equations.

The inscribed structure method, applicable for wind loads, is a means of facilitating the calculation of shear wall sheathing lengths where building geometry is non-rectangular - by inscribing the overall building into one rectangle. This Design Aid was developed as supplemental information for the Wood Frame Construction Manual (WFCM) for One- and Two-Family Dwellings to facilitate the design of inscribed versus separate structures.

This document provides a handy series of shear and moment diagrams with accompanying formulas for design of beams under various static loading conditions. Configurations include simple span, cantilever, and 2-span continuous beams.

This document describes how interior shear walls are designed to resist lateral loads. AF&PA's Wood Frame Construction Manual (WFCM) for One- and Two-Family Dwellings, 2001 Edition and Special Design Provisions for Wind and Seismic (Wind & Seismic), 2005 Edition, each provide design criteria for shear walls. Note that design assumptions are different for wind loads versus seismic loads. While wind loads act primarily on the “skin” of the structure, seismic loads are developed internally due to weight of materials and components in the structure. Therefore, certain provisions for interior shear walls may only apply to seismic loads and not wind loads.