Girder Roof Truss Design
2 roof floor truss manual 7 31 08 10 43 am page 4.
Girder roof truss design. Girders may also be designed to accommodate special applications or designs. The top chord is always in compression and the bottom chord is always in tension. Girder trusses are designed to carry additional loads other than standard roof loads. 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.
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. Longer spans with engineered lumber today it s possible to span further and hold larger loads with trusses built using engineered lumber. A girder truss is designed to support other secondary roof supports. Top general geometry for efficient structural performance the ratio of span to truss depth should be chosen in the range 10 to 15.
Basically a girder truss is usually a larger stronger truss that acts as a beam or girder. Mitek trusses provide more design flexibility inside and out than con ventional framing. Offering numerous custom design options our trusses present an economical and struc turally superior method for rapid erection. Just as there are many types of roofs with many roof parts there are many different types of roof trusses this extensive article explains through a series of custom truss diagrams the different truss configurations you can use for various roofs.
This free online truss and roof calculator generates the axial forces and reactions of completely customisable 2d truss structures. 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. This rafter truss calculator has a range of applications including being used as a wood truss calculator roof truss calculator roof rafter calculator scissor truss calculator or for roof framing. The truss plate manufacturer s engineer usually reviews and seals the individual truss designs on behalf of the truss fabricator.
They have a top chord and a bottom chord separated by diagonal webs and vertical webs. Girder trusses have a long straight design. While this article focuses on configurations we also have a very cool set of illustrations showcasing the different parts anatomy of roof trusses. Buildings constructed in l or t shapes use girder truss systems where the roof changes direction.
Using these structures in roof design eliminates the need for a load bearing wall below resulting in open floor plans.