TPI 3 Project Committee Overview

The purpose of the TPI 3 Project Committee (PC) is to develop a new American National Standard, "Design of Bracing for Metal Plate Connected Wood Trusses"
(revision and expansion of DSB-89).


TPI 3 PC Scope

This standard will provide information on the design of temporary and permanent bracing of metal plate connected wood trusses. Included will be basic bracing principles, installation loads, methodology for determining maximum spacing of temporary lateral braces along chords and webs under installation loads, methodology for determining what forces the lateral braces (temporary or permanent) must resist, methodology for designing the temporary and permanent bracing and bracing connections (using stress-rated lumber alone or in combination with commercially available structural steel truss bracing systems), horizontal diaphragms, t-bracing, permanent bracing for lateral stability (gable end bracing, sway bracing, etc.), and strongbacking and cross bridging.

Additional TPI 3 scope clarification/project information:

  1. The ultimate goal of the current TPI 3 project committee is to develop an ANSI consensus standard that provides an analytical method for safely and efficiently designing temporary and permanent bracing for Metal Plate Connected Wood Truss systems.
  2. It is expected that this design methodology will produce bracing requirements consistent with those prescribed in the BCSI but will (in most cases) generate more efficient designs and cover a broader range of truss system types.
  3. The project committee will become familiar with and utilize past DSB 89 and BCSI work as a foundation for further developments.
  4. Although the new TPI 3 Standard will only address Metal Plate Connected Wood Trusses, the project committee will consider the methods prescribed in the CFS BCSI in order to maintain bracing consistency as much as practical.
  5. Applicable information from SBC Research Institute (SBCRI) testing that becomes available during the development of the TPI 3 standard and testing projects that include testing of bracing concepts will be considered as a means to verify engineering assumptions as appropriate and fill gaps in knowledge where needed to create bracing design methodologies.  
  6. In order to coordinate efforts, the project committee will stay in close contact with SBCRI testing.  It is currently envisioned that the first edition of the TPI 3 standard will be a separate but complimentary document to the design methodology undergirding BCSI and will provide design methodologies for conventional methods of bracing wood truss systems, yet encourage new and innovative methods that may be included in later versions of the TPI 3 standard and future BCSI guides.
  7. The work of the current TPI 3 PC is estimated to take 24 months to complete.

The PC operates in accordance with the TPI Project Committee Method to Achieve Consensus (PCMAC).

Project Status - PUBLIC REVIEW PERIOD NOW OPEN

A second Public Review of the draft TPI 3-201X standard has been initiated (Press Release). Those wishing to comment on this draft of the standard (available HERE) should submit comments to TPI using the TPI 3-201X Public Review COMMENT SUBMITTAL FORM prior to the close of the Public Review period on October 19, 2015.

Printed copies of the draft standard are also available for $20 each plus tax and shipping & handling (prepaid by check or money order) and can be ordered directly from TPI at 218 North Lee Street, Suite 312, Alexandria, VA 22314, (703) 683-1010.