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Manufacture


Truss



The computer design of light frame trusses results in the generation of fabrication instructions that indicate the precise cutting patterns for each of the members and the type, size, and location of connector plates required. A layout template is made for each configuration to ensure that like trusses are identical in dimension. The member pieces are cut to correct dimension and assembled in the template, which is located on a floor, truss jig, or heavy table. The cutting drawings show a sketch of the truss and contain the following important information:

  • overall truss dimensions
  • location of all supports
  • web and chord sizes and grades
  • plate size, type, and location for each joint

  • The chords and webs are connected together by the use of truss plates, which transfer the tensile, compressive and shear forces. Identical truss plates are placed directly opposite each other on opposing faces and are pressed into the wood members using hydraulic platen ( plates ) presses or rollers.


    Figure 4: Manufacturing of Light Frame Trusses



    Click picture to enlarge view.


    When the pressing of the plates has been completed, the trusses are checked for dimensions, wood to wood gaps, lumber size and species, plate size, positioning and embedment and moved to a storage area. In some cases plants have a quality control program that ensures consistency in production and quality in place of checking each truss. The completed trusses are then strapped together and placed in the storage yard in preparation for shipping.