SBCA's Sample TPD Note Language to Define CM Scope of Work

The following article provides SBCA's proposed best practice Truss Placement Diagram note language for CMsto use as a standardize approach with respect to defining their scope of work.

Proposed Sample TPD Note Language

The Truss Placement Diagram(s) (“TPD[s]”) referenced have been prepared based on the Construction Documents prepared by the Building Designer indicating the nature and character of the design of the Building, including the Building Structural System. The design criteria from the Construction Documents have been transferred to _____________ (Engineering Firm) by [Plant Location]. These TDDs set forth structural component designs and may be part of a Building’s deferred or phased submittals. The Truss Design Engineer’s (also referred to in some Jurisdictions as a “Delegated or Specialty Engineer”), seal on this Cover Sheet and on any TDD represents an acceptance of professional engineering responsibility for the design of the single Truss depicted on the TDD only. The Building Designer is responsible for and shall coordinate and review the TDDs for compatibility with the Construction Documents and the Building Structural System. All capitalized terms not otherwise defined herein are as defined in ANSI/TPI 1, the National Design Standard for Metal Plate Connected Wood Truss Construction (“TPI-1”).

Where required by Contract between the component manufacturer (“CM”) and the Contractor or Owner or the Construction Documents or Building specifications, a TPD identifying the location of each Truss, as assumed by ____________ [CM] based on its review of the Building Contract if provided and the Construction Documents including any Building specifications, will be provided. When the TPD is provided it serves only as a guide for Truss installation, it does not require the seal of any registered design professional (“RDP”).

________ [Engineering Firm]’s seal on any TPD certifies that the individual TDDs are based on the location of each Truss shown and that the dimensions and loads shown on the referenced drawings match that location. ________ [Engineering Firm]’s seal designates specifically that TPD has been created in compliance with the latest version of TPI 1.

All Trusses have been designed and are to be manufactured pursuant to TPI-1. The design assumptions, loading conditions, suitability and use of the Trusses depicted shall be verified by both the Contractor and Building Designer.

The approval of the TDDs and Truss Placement Diagrams (“TPD[s]”) and any field of use of the Trusses, including handling, storage, installation and bracing, is the responsibility of the Building Designer and Contractor. The Truss Design Engineer is NOT the Building Designer or Truss System Engineer (as that term is defined in some Jurisdictions) for any Building.

The Truss Design Engineer is NOT responsible for the following including but not limited to:

  • Transfer of vertical and lateral loads and all load paths to the foundation,
  •      Transfer of lateral load from the roof to the shear walls,
  •      Connection of Trusses to the bearing support,
  •      Design of the bearing supports,
  •      Temporary and permanent building  stability bracing required in the roof and/or floor system,
  •      Design of soil and foundation,
  • Analysis of the roof and/or floor diaphragms of the building,
  • Connection of roof and/or floor diaphragm to the Truss,
  • Specifying the loads used in the design of the Trusses and so forth.

This Truss Submittal Package contains all information required under Chapter 2 of TPI 1 including TDDs, which have been sealed where required, and which generally depict the individual Trusses to be manufactured for the Building(s).

This TPD is submitted for your review. Please also submit or cause to be submitted this Truss Submittal Package to the Building Designer for review and approval or for a notation that specific corrections are noted for re-submittal.

The Building Designer’s review shall include confirmation of the loading conditions, suitability and use of the Trusses with respect to the Building(s). Internal Truss web configuration, splicing of Truss chord members and other details relating to Truss design are subject to change by ______ [name of Truss Manufacturer] at the time of the final preparation of the TDD and for Truss manufacturing.  Slight changes in Truss reactions and deflections may also occur as a result of any refinement of the final Truss design. All changes will be reflected in the TDDs provided in the Truss Submittal Package delivered to the jobsite

If any engineering services, outside the scope of work of the Truss Design Engineer, are required by the Building Designer, please call ________________ for assistance.