TrusSteel - Cold Formed Steel Trusses

1 2 3 4 5 6 7 8 3.03 Building Use Building regulations differ for various types of use and occupancy. Specific classifications of use are: single family residential, multi-family residential, offices, retail, manufacturing, churches, institutions (long-term care, nursing homes, schools, hospitals, jails, etc.) or agricultural (non-human occupancy). There are also fire protection requirements for buildings that may require the CFS members and assemblies to perform in specific manners. At times, the CFS truss system may be required to perform in an atmosphere that may be corrosive to CFS members. It is important to properly specify the level of protection that will be required to keep the underlying steel safe from damage by this atmosphere. Applicable Building Code Clearly identify the Applicable Building Code for the specific site location (also called the Building Code of Jurisdiction). Geometry of the Structure Furnish span (out-to-out of bearings, plus cantilevers, if any), slope, overhang conditions, etc. that form the profiles or external geometry of the trusses. Truss web configurations need not be furnished, as they are determined by the overall truss design. Truss Bearings Specify all exterior and interior points of bearing, showing location by dimensions, size, and elevation above ground or benchmarks. It is important to specify the type of bearing material to be used to properly design connections to the bearing. Required information could include grade of steel, grade of wood, strength of concrete, etc. Truss Spacings Give desired center-to-center spacings of trusses. Truss Restraint When designing trusses, it is important that the truss designer know how the truss chords will be restrained. The two most common methods of restraint are structural sheathing and purlins. In the structural sheathing method, sheathing - most commonly plywood, oriented strand board (OSB), and metal deck (such as B-deck) - is applied directly to the truss chords. The design and connection of these decks to the trusses is the responsibility of the building designer. In the purlin method, CFS members used as purlins are attached directly to the truss chord to properly support the truss chord laterally. CFS hat channels or Z shaped members are commonly used as purlins. This method is typically used when the sheathing material is not capable of spanning the distance between trusses. The design and connection of the purlin members is the responsibility of the building designer. Truss manufacturers need certain specific information on every project in order to design and fabricate trusses. As a building designer, specifier or installer, you can help expedite your order and assure proper fit by providing the following information to the truss manufacturer. Support of Mechanical Equipment Trusses under mechanical units must be specifically designed. If the building designer is relying on the sheathing to support the mechanical load or other heavy load, it is important that the building designer verify the sheathing thickness and capability. Mechanical loads may produce sufficient vibration to be considered in the truss design. Such loads may require additional trusses or custom design. INFORMATION REQUIRED FOR TRUSS DESIGN ENGINEERED BY ALPINE S P E C I F Y I N G / D E S I G N I N G

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