Girder Roof Truss Design

Girder trusses are designed to carry additional loads other than standard roof loads.

Girder roof truss design.

Trusses are triangular formations of steel sections in which the members are subjected to essentially axial forces due to externally applied load. These loads can be other trusses that attach by sitting on top of the girder or they may attach to the side of the girder using truss hangers. They have a top chord and a bottom chord separated by diagonal webs and vertical webs. Using these structures in roof design eliminates the need for a load bearing wall below resulting in open floor plans.

Buildings constructed in l or t shapes use girder truss systems where the roof changes direction. Girder trusses have a long straight design. Girders may also be designed to accommodate special applications or designs. The truss plate manufacturer s engineer usually reviews and seals the individual truss designs on behalf of the truss fabricator.

The roofing system for such buildings is truss with roof covering material. Typically the building designer or builder will contract with the truss fabricator who will supply a truss layout and a structural design of each significant element of the roof system. Top general geometry for efficient structural performance the ratio of span to truss depth should be chosen in the range 10 to 15. An advantage of the truss design for roofs is that ducts and pipes that are required for operation of the buildings services can be installed through the truss web i e.