CEMP-E
TI 809-07
NOVEMBER 1998
difference in thickness. Then the material should be coated with a minimum of ASTM A294, G60
galvanized coating for corrosion protection. The following is a listing of the material's design
thickness used in the Prescriptive Methods code. Also, this code has developed a standard
method for marking each stud. The industry identifier of 350S162-068 is read as a 39 mm (3.50
") Stud with a 41 mm (1.62 ") flange and a material thickness of 1.81 mm (68 mils). In general
studs used in this code are the same overall dimensions as their wood stud counterpart.
Bearing Walls: 0.84, 1.09, 1.37, 1.72, 2.45 mm (33, 43, 54, 68, 97 mils)
Nonstructural Walls: 0.46, 0.68 mm (18, 27 mils)
Joists/Rafters: 0.84, 1.09, 1.37, 1.72, 2.45 mm (33, 43, 54, 68, 97 mils)
Ceiling Joists: 0.84, 1.09, 1.37, 1.72, 2.45 mm (33, 43, 54, 68, 97 mils)
Strapping: 0.84 mm (33 mils)
c. Engineered Portions of the Prescriptive Code. When using the Council of American
Building Officials (CABO) Prescriptive Code (National Association of Home Builders report) there
are many conditions that need to be checked by the design engineer. When using the
Prescriptive method, the design engineer shall check the selection of the buildings main structural
members, as this method uses building loads from ASCE 7-93. The design loads will be
upgraded to the most current ASCE 7 standard. The following components are engineered
portions of the prescriptive code.
Sheathing selection and design when over 145 Km/hr (90 mph) winds and seismic
zones 3 and 4
Hybrid systems that use steel and wood
Wall bracing, hold-downs and uplift straps for Winds loads greater than 145 Km/hr
(90mph), and for Seismic Zones 3 and 4
Pneumatically driven fasteners, powder actuated fasteners, crimping, and welding
Overhangs, balconies, and decks with live loads greater than 1.92 KPa (40 psf)
Floor joist splices and the design and bracing of Cold-formed Steel floor trusses
In-line blocking every 3.7 m (12 ft) on strap braced studs
The approval of corner framing details
Steel strapping and `X' bracing
Cathedral ceilings
Wood rafters
Ceiling joist and rafter splices
Steel and/or wood roof trusses and associated bracing systems
King stud and wall stud uplift straps and end gable uplift straps
Load carrying track members
3. COLD-FORMED STEEL FRAMING.
a. General. There are many differences when steel designers start using lightweight steel
framing systems. Generally cold-formed sections are shaped and formed from flat sheets, their
original mechanical properties are changed during cold-forming, there are no standard shapes,
the thickness of materials are generally less then 3 mm (1/8 inch) thick, and the predominate
failure mode is buckling followed by a post-buckling strength increase.
b. Design Guidance. Guidance from the American Iron and Steel Institute (AISI) applies to
materials with a thickness that is less than 5 mm (3/16 inch) thick for connections, and plate up to
25 mm (1 inch) can be cold-formed. Guidance from the American Institute of Steel Construction
(AISC) applies to thicker materials. When using cold-formed stainless steel, design requirements
can be found in American Society of Civil Engineers (ASCE) criteria. The 1996 AISI specification
covers material usage, loading combinations (ASCE 7), the structural analysis of elements,
members, and assemblies, the design of connections and joints, and the testing for special
cases.
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