Various loads acting over the truss are calculated using the provisions of IS875 (Parts … In North America, wood roof •Transfers the load of the roof through the raftersto walls below. Crescent roof trusses 3. Method of sections: Monday, November 02, 2009 8:53 AM CE297 -FA09 -Ch6 Page 8 . – Seek professional guidance if anything is unclear. The main purpose of a roof is to protect the house in all types of weather with a minimum of maintenance. Wood trusses are very versatile and compatible with other structural products. 8. Triangular roof trusses 2. When a roof is to be provided for a building which does not have interior supports and the exterior walls are more than 12 m apart, a roof truss will be a convenient arrangement to support the roof. In modern double roof construction, the whole of the roof is constructed of lightweight roof trusses called trussed rafters (See Module 4). Draw FBD of the 2 different parts of the truss Enforce Equilibrium to find the forces in the 3 members that are cut. 7 Buckling Calculations 2 weak cr 2 EI P ( L) buckling force π = = k effective length factor 1for an ideal truss member = = k k. 8 Types of Trusses Basic Truss Element ≡three member triangular truss Simple Trusses – composed of basic truss … 6. • Factory-manufactured components to exact span requirements • Reduced HVAC, plumbing, and electrical subcontractor time on job • No column pads to pour, no steel beams and posts to place • Job site material pilferage and cutting waste reduced TM ADVANTAGES OF TRUSSES OVER CONVENTIONAL FRAMING Roof-Floor Truss manual 7/31/08 10:43 AM Page 5 Repair the truss by following the information provided in the TRDD exactly. CE297 -FA09 -Ch6 Page 9 . and roof design. One of the technical drawings of the building is shown in figure 3 below. The top chords are straight. GANG-NAIL Truss System From these examples, it can be readily appreciated that timber trusses are very effective structural components. Common Roof Trusses 5. This technical drawing is modelled in CAD software and analysis then takes place. 5. discussion of the types and parts of roof trusses. Triangular Roof Trusses: These contain the most common types of trusses used for building. – If the truss is already installed, shore up the truss to relieve any load. girder trusses) or combined with other components, such as glulam, LVL, PSL and steel beams. Components of a Steel Roof Truss: This will depend upon the size of the roof and the type of roof covering the roof has to support. 1. TERMINOLOGY LEARNING OBJECTIVE: Upon completing this section, you should be able to identify the types of roofs and define common roof framing terms. Supported by lally columns. Roof trusses other than these 1. They can be connected to other trusses (i.e. Truss roof framing is cov-ered in Section 17.4. 6.8 Compound Trusses; Determinate vs. Indeterminate Trusses. Prior to beginning the repair, lay the truss flat on a solid, level surface. For many single storey buildings sloping roofs on trusses are common. trusses. A roof … Parts of a Roof •A Ridge Board is a horizontal member of the roof frame. In traditionally constructed roofs, the roof may also require added support in the form of roof trusses. igure 12 russ Analysis and Member Design and a truss shape has been chosen, the truss can be s are subjected to combinations … Triangular roof trusses may be identified by the web bracing used and the simple triangular geometric shape used throughout their design. Depending upon the span, required lighting, and available roofing material, the type of truss is selected and a line diagram of the truss is sketched 2. Attic trusses are designed to provide living areas within the roof space. Figure 3 Technical drawing of truss and column assembly The roof must be appropriate for the climate in which the house is being built. The point at which all the rafters are attached to. the roof truss, column support and joints are assumed to be the most crucial parts. This is demonstrated later. 2. A roof must be strong to withstand snow and wind loads. •Ridge Beam sits below the rafters. The primary object of a roof in any climate is protection from the elements. Make sure to use the correct materials as specified. Framing of a Roof Supported Truss. The various steps involved in the design of truss members are as follows: 1. 4.