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Canam joists-and-girders-catalogue-canada

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Canam has been producing open-web steel joists for over 50 years and has developed expertise in engineering and fabrication to better serve our customers with quality products. This guide was developed to assist engineers in the specification of Canam joist girders.

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Canam joists-and-girders-catalogue-canada

  1. 1. Joist Catalogue Joists and Joist Girders A division of Canam Group
  2. 2. Canam is a trademark of Canam Group Inc. TABLE OF CONTENTS Products, services and solutions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 General information The advantages of using steel joists . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Description of a joist girder. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Components of a joist girder. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Advantages of joist girders. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Design standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Quality assurance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Accessories Material / Metric. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Axes convention. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Section properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Material / Imperial. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Axes convention. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Section properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Bridging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Bridging line requirements / Metric. . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Bridging line requirements / Imperial . . . . . . . . . . . . . . . . . . . . . . . . . 15 Spacing for bridging / Metric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Spacing for bridging / Imperial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Knee braces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Material weights. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Standard details Extensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Maximum duct openings / Metric. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Maximum duct openings / Imperial . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Geometry and shapes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Standard shape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Non-standard shapes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Special shapes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Minimum depth and span . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Shoes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Particularities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Bearing on concrete or masonry wall. . . . . . . . . . . . . . . . . . . . . . . . 29 Bearing on steel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Details. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Ceiling extension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Flush shoe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Bolted splice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Bottom chord bearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Cantilever joist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Joist and joist girder identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Standard connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Surface preparation and paint Paint standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Paint costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Colours . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Joists exposed to the elements or corrosive conditions. . . . . . . . . . 34 Vibration Steel joist floor vibration comparison . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Special conditions Special joist deflection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Deflection of cantilevered joists. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Camber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Special loads and moments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Various types of loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Transfer of axial loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Unbalanced loads. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Load reduction according to tributary area . . . . . . . . . . . . . . . . . . . . . 42 End moments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Gravitational moments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Wind moments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Joist or joist girder analysis and design. . . . . . . . . . . . . . . . . . . . . . 44 Joists adjacent to more rigid surfaces . . . . . . . . . . . . . . . . . . . . . . . . . 46 Joists with lateral slope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Anchors on joists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Special joists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Joist girder to column connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Bearing reaction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Bearing on top of the column. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Bearing facing the column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 Bearing facing the column with center reaction . . . . . . . . . . . . . . 50 Standards CAN/CSA S16-01 standards (16. Open-web steel joists) and CISC commentaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Joist depth selection tables Metric. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 Imperial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 Joist girder depth selection. . . . . . . . . . . . . . . . . . . . . . . . . . 89 Graphics / Metric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Graphics / Imperial. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 Joist girder specifications Information required from the building designer . . . . . . . . . . . . . . . . 97 Checklist - joist Joist design essential information checklist . . . . . . . . . . . . . . . . . . . . 98 Take-off sheet - quotation. . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 Sales offices and plant certifications. . . . . . . . . . . . . . 103
  3. 3. Canam specializes in the fabrication of steel joists, joist girders, steel deck, purlins and girts, and welded wide-flange shapes. We also design and fabricate the Murox® high performance building system and Econox foldaway portable buildings. Canam offers customers value-added engineering and drafting support, architectural flexibility and customized solutions and services. Another Canam solution, the BuildMaster™ approach, has redefined the way in which buildings are designed and built by offering a safer, faster and greener process that can reduce field erection time by between 15% and 25%. Factors such as product quality, worksite supervision and construction time are critical in the execution of any project, big or small, and Canam's reputation for reliability simplifies these considerations for customers. In addition to a rigorous jobsite management process that is specifically designed to ensure that deadlines are met, our cutting-edge equipment, skilled employees and high quality products are also key in allowing Canam to keep its promises. Whatever your project, we will meet your requirements while also complying with all applicable building codes. Another aspect of our exceptional service is just-in-time delivery as per customer specifications. To eliminate delays, components are transported by our very own fleet, which stands ready to ensure on-time delivery, regardless of the location. Depending on the region and worksite, Canam can transport components measuring up to 16 ft. (4.9 m) wide and 120 ft. (36.5 m) long. Canam is one of the largest steel joist fabricators in North America. Cautionary statement Although every effort was made to ensure that the information contained in this catalog is factual and that the numerical values presented herein are consistent with applicable standards, Canam does not assume any responsibility whatsoever for errors or oversights that may result from the use or interpretation of this data. Anyone making use of this catalog assumes all liability arising from such use. All comments and suggestions for improvements to this publication are greatly appreciated and will receive full consideration in future editions. 4 Products,services and solutions
  4. 4. The advantages of using steel joists Using a steel joist and steel deck system for floor and roof construction has proven itself to be a most advantageous solution. It can result in substantial savings based on: • Efficiences of high-strength steel; • Speed and ease of erection; • Low self-weight of roof and floor construction allowing for smaller columns and foundations than for a concrete structure; • Increased bay dimensions, which reduces the number of joists and columns and simplifies building erection; • Greater floor plan layout flexibility for the building occupant due to the increased bay dimensions; • Maximum ceiling height due to installation of ducts through the joist web system; • Easy adaptation to acoustical insulation systems; • Floor and roof composition having long-term resistance to fire, as established by the Underwriters Laboratories of Canada (ULC). DESCRIPTION OF A JOIST GIRDER DEFINITION A joist girder is a primary structural component of a building. Generally, it supports floor or roof joists in simple span conditions, or other secondary elements (purlins, wood trusses, etc.) evenly spaced along the length of the joist girder. The loads applied to a spandrel joist girder come from one side, while on an inside bay the loads are applied on either side of the joist girder. COMPONENTS OF A JOIST GIRDER An open web joist girder, or commonly known as a “cantruss” at Canam, is composed of a top chord and a bottom chord, which are usually parallel to each other. These chords are held in place using vertical and diagonal web members. In conventional construction, a joist girder rests on a column and the bottom chord is held in place horizontally by a stabilizing plate. The standard main components are: 1. Top and bottom chords: two angles back-to-back with a gap varying between 25 mm (1 in.) and 76 mm (3 in.), 2. Diagonals: U-shaped channels or two angles back-to-back, 3. Verticals: U-shaped channels, boxed angles or HSS, 4. Shoes: two angles back-to-back. Top chord Bottom chordDiagonal Vertical Shoe Components of a joist girder Appuis sphériques 5 General information
  5. 5. ADVANTAGES OF JOIST GIRDERS The use of open web joist girders is widespread in North America, mostly in the United States, for roof construction of commercial and industrial buildings. The joist girders are advantageous compared with conventional load bearing systems composed of beams with a W profile. Here are the various options for supporting systems when designing a steel building: Economical factors associated with the specification of joist girders include the following: 1. The steel used in joist girders has a yield strength higher than steel used for shaped or welded beams: 380 MPa (55 ksi) versus 350 MPa (50 ksi). 2. Better cost control for material purchases (angles) on the Canadian market compared with importing the beam sections. 3. Open web joist girders are lighter than the full web beams of the same depth. 4. The speed and ease of site erection improves jobsite co-ordination. 5. The joist girders can be used to facilitate the installation of ventilation ducts and plumbing as compared to a beam. Carrying system Simple beam Gerber system Joist girder Beam Joist girder Mechanical conduits Passage of mechanical conduits Appuis sphériques 6 General information
  6. 6. If a larger opening is required, a diagonal member can be removed if the top and bottom chord are reinforced. The building designer must consider the following to ensure the economical use of joist girders: 1. Longer spans of joist girders are preferred as this reduces the number of columns inside a building. 2. Greater depths reduce the size of the top and bottom chords for increased weight savings. 3. Bay arrangement should be repetitive since designing and fabricating many identical pieces will reduce production costs. 4. Regular joist spacing must be maintained by the building designer by lining up the joists on either side of the joist girders. 5. Rectangular bays are recommended, in a roof or floor system using joist girders and joists, where the longest dimension corresponds to the joist span, while the shortest dimension corresponds to the joist girder span. An optimal rectangular bay would typically have a ratio of joist span to joist girder span of approximately 1.5. 6. Bearing shoes are used for economical joist girder to column connection, usually 191 mm (7.5 in.) deep, bolted to the top of the column or on a bearing bracket on the web or the flange of the column. STEEL Our joist and joist girder design makes use of high strength steel purchased in accordance with the latest issue of the standards below: • Cold formed angles and U-shaped channels: ASTM A1011; • Hot rolled angles and round bars: CAN/CSA-G40.20/G40.21. DESIGN STANDARDS Joist and joist girder design is based on the latest issue of the design standards in effect: Canada: United States: • CAN/CSA S16–01 • SJI • CAN/CSA S136–07 • NBCC 2005 QUALITY ASSURANCE Over the years, we have established strict quality standards. All our welders, inspectors, and quality assurance technicians are certified by the Canadian Welding Bureau (CWB). We do visual inspections on 100% of the welded joints and non-destructive testing if required. Optimal rectangular bay Joist girder Joist girder Approximately1.5xL Joists L Distribution Centre I Cornwall, Ontario Cold formed angle Hot rolled angle Notes: This catalog was produced by Canam, a business unit of Canam Group Inc. It is intended for use by engineers, architects, and building contractors working in steel construction. It is a selection tool for our economical steel products. It is also a practical guide for Canam joists and joist girders. Canam reserves the right to change, revise, or withdraw any product or procedure without notice. The information presented in this catalog was prepared according to recognized engineering principles and is for general use. Although every effort has been made to ensure that the information in this catalog is correct and complete, it is possible that errors or oversights may have occurred. The information contained herein should not be used without examination and verification of its applications by a certified professional. 7 General information
  7. 7. XX Y Y XX Y Y y xx Y Y xx y y Material Metric Material (in.) Grade (MPa) Forming Mass (kg/m) Area (mm2 ) l (103 mm4 ) r (mm) 1/2 350 Hot rolled 0.99 127 1.28 3.2 9/16 350 Hot rolled 1.26 160 2.05 3.6 5/8 350 Hot rolled 1.55 198 3.11 4.0 11/16 350 Hot rolled 1.88 239 4.56 4.4 3/4 350 Hot rolled 2.24 285 6.46 4.8 13/16 350 Hot rolled 2.62 335 8.91 5.2 7/8 350 Hot rolled 3.05 388 11.99 5.6 15/16 350 Hot rolled 3.49 445 15.78 6.0 1 350 Hot rolled 3.97 507 20.43 6.4 1 1/8 350 Hot rolled 5.03 641 32.73 7.1 1 square 350 Hot rolled 5.06 645 34.69 7.3 Axis X-X Axis Y-Y Material Grade (MPa) Forming Mass (kg/m) Area (mm2) y (mm) lxx (103 mm4) rxx (mm) lyy (103 mm4) ryy (mm)(in.) (in.) (in.) 1 x 5/8 x 0.090 350 Cold formed 0.84 107 5.1 2.13 4.4 9.30 9.3 1 x 0.8 x 0.090 350 Cold formed 1.01 129 7.1 4.81 6.1 12.18 9.7 1 x 0.85 x 0.090 350 Cold formed 1.07 137 7.8 5.99 6.6 13.11 9.8 1 x 1 x 0.090 350 Cold formed 1.15 146 8.7 7.71 7.3 14.25 9.9 1 x 1 x 0.118 350 Cold formed 1.49 191 9.6 10.70 7.5 17.55 9.6 1 x 1.05 x 0.090 350 Cold formed 1.28 161 10.4 11.61 8.5 16.38 10.1 1 x 1.1 x 0.118 350 Cold formed 1.68 212 11.4 16.20 8.7 20.36 9.8 1 3/8 x 1.27 x 0.118 350 Cold formed 2.11 268 12.1 28.02 10.2 52.23 13.9 1 3/8 x 1 3/8 x 0.118 350 Cold formed 2.21 283 13.1 34.03 11.0 55.72 14.0 1 3/8 x 1 3/8 x 0.157 350 Cold formed 2.94 374 14.3 46.87 11.2 69.47 13.6 1 3/4 x 1 1/2 x 0.157 350 Cold formed 3.45 440 14.5 66.68 12.3 138.13 17.7 1 3/4 x 1 3/4 x 0.197 350 Cold formed 4.67 597 18.0 120.22 14.2 183.92 17.6 2 3/8 x 2 x 0.197 350 Cold formed 5.57 711 18.0 171.57 15.5 396.63 23.6 rOUND AND SQUARE BARS U Shapes Section properties Axes convention 8 Accessories
  8. 8. Double angles (long legs back-to-back) MEtriC Axis X-X ryy with different gaps Axis Z Material Grade (MPa) Forming Mass (kg/m) Area (mm2) y (mm) lxx (106 mm4) rxx (mm) 12.7 (mm) 19 (mm) 25 (mm) 35 (mm) 45 (mm) 60 (mm) rz (mm)(in.) (in.) (in.) 1 x 1 x 0.090 380 Cold formed 1.74 215 7.4 0.013 7.8 15.8 18.6 21.4 26.1 30.9 38.2 4.9 1 x 1 x 7/64 380 Hot rolled 2.09 266 7.4 0.016 7.8 15.8 18.6 21.3 26.1 30.9 38.2 5.0 1 x 1 x 0.118 380 Cold formed 2.22 275 7.8 0.017 7.8 16.1 19.0 21.7 26.5 31.3 38.6 4.8 1 x 1 x 1/8 380 Hot rolled 2.38 296 7.5 0.018 7.7 15.9 18.7 21.5 26.2 31.0 38.3 5.0 1 1/8 x 1 1/8 x 0.090 380 Cold formed 1.97 244 8.2 0.019 8.9 17.0 19.8 22.5 27.2 31.9 39.2 5.5 1 1/8 x 1 1/8 x 0.118 380 Cold formed 2.53 313 8.6 0.024 8.8 17.3 20.1 22.8 27.5 32.3 39.6 5.5 1 1/4 x 1 1/4 x 0.118 380 Cold formed 2.84 351 9.4 0.034 9.8 18.5 21.3 24.0 28.6 33.3 40.6 6.1 1 1/4 x 1 1/4 x 1/8 380 Hot rolled 3.00 387 9.1 0.037 9.8 18.3 21.0 23.7 28.4 33.1 40.3 6.2 1 1/4 x 1 1/4 x 3/16 380 Hot rolled 4.40 555 9.7 0.051 9.6 18.7 21.4 24.2 28.8 33.6 40.8 6.2 1 3/8 x 1 3/8 x 0.118 380 Cold formed 3.14 390 10.1 0.046 10.9 19.8 22.5 25.1 29.7 34.4 41.6 6.8 1 1/2 x 1 1/2 x 0.118 380 Cold formed 3.45 428 10.9 0.061 11.9 21.0 23.6 26.3 30.8 35.5 42.6 7.4 1 1/2 x 1 1/2 x 1/8 380 Hot rolled 3.66 465 10.7 0.065 11.8 20.7 23.4 26.0 30.6 35.2 42.4 7.5 1 1/2 x 1 1/2 x 5/32 380 Hot rolled 4.49 573 11.0 0.079 11.7 20.9 23.6 26.2 30.8 35.5 42.6 7.5 1 1/2 x 1 1/2 x 0.157 380 Cold formed 4.47 557 11.4 0.077 11.7 21.3 24.0 26.7 31.2 35.9 43.1 7.3 1 1/2 x 1 1/2 x 3/16 380 Hot rolled 5.36 684 11.3 0.092 11.6 21.1 23.8 26.5 31.0 35.7 42.9 7.5 1 5/8 x 1 5/8 x 0.118 380 Cold formed 3.76 466 11.7 0.078 12.9 22.2 24.9 27.5 32.0 36.6 43.7 8.1 1 5/8 x 1 5/8 x 0.157 380 Cold formed 4.87 608 12.2 0.099 12.8 22.5 25.2 27.8 32.3 37.0 44.1 8.0 1 3/4 x 1 3/4 x 0.118 380 Cold formed 4.06 504 12.5 0.098 13.9 23.5 26.1 28.6 33.1 37.7 44.8 8.7 1 3/4 x 1 3/4 x 5/32 380 Hot rolled 5.31 674 12.6 0.128 13.8 23.4 26.0 28.6 33.1 37.7 44.8 8.8 1 3/4 x 1 3/4 x 0.157 380 Cold formed 5.28 659 13.0 0.126 13.8 23.8 26.4 29.0 33.5 38.1 45.2 8.6 1 3/4 x 1 3/4 x 3/16 380 Hot rolled 6.31 800 12.9 0.149 13.6 23.6 26.2 28.8 33.3 37.9 45.0 8.7 1 7/8 x 1 7/8 x 0.157 380 Cold formed 5.69 709 13.8 0.156 14.8 25.0 27.6 30.2 34.6 39.2 46.2 9.3 1 7/8 x 1 7/8 x 0.197 380 Cold formed 6.96 870 14.3 0.188 14.7 25.3 27.9 30.5 35.0 39.6 46.7 9.1 2 x 2 x 0.118 380 Cold formed 4.66 580 14.1 0.148 16.0 26.0 28.5 31.0 35.4 39.9 46.9 10.0 2 x 2 x 0.157 380 Cold formed 6.10 760 14.6 0.191 15.8 26.3 28.8 31.4 35.8 40.3 47.3 9.9 2 x 2 x 3/16 380 Hot rolled 7.26 916 14.5 0.227 15.7 26.1 28.6 31.2 35.6 40.2 47.1 10.0 2 x 2 x 0.197 380 Cold formed 7.46 934 15.1 0.231 15.7 26.6 29.2 31.7 36.2 40.7 47.7 9.8 2 x 2 x 7/32 380 Hot rolled 8.37 1 068 14.7 0.259 15.6 26.2 28.8 31.4 35.8 40.4 47.4 10.0 2 x 2 x 1/4 380 Hot rolled 9.50 1 213 15.0 0.289 15.5 26.4 29.0 31.6 36.0 40.6 47.6 9.9 2 1/8 x 2 1/8 x 0.157 380 Cold formed 6.50 811 15.4 0.231 16.9 27.5 30.1 32.6 37.0 41.5 48.4 10.6 2 1/8 x 2 1/8 x 0.197 380 Cold formed 7.97 997 15.9 0.280 16.7 27.8 30.4 32.9 37.3 41.9 48.8 10.4 2 1/8 x 2 1/8 x 0.236 380 Cold formed 9.39 1 181 16.3 0.324 16.6 27.8 30.4 33.0 37.3 41.9 48.9 10.3 2 1/4 x 2 1/4 x 0.197 380 Cold formed 8.48 1 061 16.6 0.335 17.8 29.1 31.6 34.1 38.5 43.0 49.9 11.1 2 1/4 x 2 1/4 x 0.236 380 Cold formed 9.99 1 253 17.1 0.390 17.6 29.4 31.9 34.5 38.9 43.4 50.3 11.0 2 3/8 x 2 3/8 x 0.197 380 Cold formed 8.98 1 124 17.4 0.398 18.8 30.3 32.8 35.3 39.7 44.1 51.0 11.7 2 3/8 x 2 3/8 x 0.236 380 Cold formed 10.60 1 330 17.9 0.463 18.6 30.6 33.2 35.7 40.0 44.5 51.4 11.6 2 1/2 x 2 1/2 x 0.197 380 Cold formed 9.49 1 188 18.2 0.467 19.8 31.6 34.1 36.6 40.9 45.3 52.1 12.4 2 1/2 x 2 1/2 x 0.236 380 Cold formed 11.20 1 406 18.7 0.545 19.7 31.9 34.4 36.9 41.2 45.7 52.5 12.3 2 1/2 x 2 1/2 x 1/4 380 Hot rolled 12.21 1 536 18.2 0.585 19.5 31.4 33.9 36.4 40.7 45.2 52.0 12.5 2 1/2 x 2 1/2 x 5/16 380 Hot rolled 14.89 1 890 18.8 0.706 19.3 31.7 34.3 36.8 41.1 45.6 52.5 12.4 2 5/8 x 2 5/8 x 0.236 380 Cold formed 11.81 1 482 19.5 0.636 20.7 33.1 35.6 38.1 42.4 46.8 53.7 12.9 2 3/4 x 2 3/4 x 0.236 380 Cold formed 12.42 1 558 20.3 0.737 21.7 34.4 36.9 39.3 43.6 48.0 54.8 13.6 2 7/8 x 2 7/8 x 0.236 380 Cold formed 13.02 1 634 21.1 0.848 22.7 35.6 38.1 40.6 44.8 49.2 55.9 14.2 3 x 3 x 0.236 380 Cold formed 13.63 1 711 21.9 0.969 23.8 36.9 39.4 41.8 46.0 50.3 57.1 14.9 3 x 2 x 5/16 350 Hot rolled 14.89 1 882 25.8 1.095 24.1 24.2 26.8 29.4 33.8 38.4 45.5 11.0 3 x 3 x 5/16 380 Hot rolled 18.16 2 291 22.0 1.256 23.4 36.7 39.2 41.7 45.9 50.3 57.0 15.0 3 x 3 x 3/8 380 Hot rolled 21.44 2 722 22.5 1.465 23.2 37.1 39.6 42.0 46.3 50.7 57.4 14.9 3 1/8 x 3 1/8 x 0.236 380 Cold formed 14.23 1 787 22.7 1.101 24.8 38.2 40.6 43.0 47.2 51.5 58.2 15.5 3 1/2 x 3 1/2 x 3/8 380 Hot rolled 25.30 3 206 25.7 2.384 27.3 42.1 44.6 47.0 51.1 55.4 62.1 17.4 4 x 3 x 3/8 380 Hot rolled 25.31 3 200 32.6 3.298 32.1 34.4 36.9 39.3 43.5 47.9 54.6 16.4 4 x 4 x 3/8 380 Hot rolled 29.19 3 691 28.9 3.630 31.4 47.2 49.6 52.0 56.0 60.2 66.7 20.0 4 x 3 x 1/2 380 Hot rolled 33.05 4 194 33.7 4.203 31.7 35.1 37.6 40.0 44.3 48.7 55.5 16.2 4 x 4 x 1/2 380 Hot rolled 38.12 4 860 30.1 4.630 30.9 47.8 50.2 52.6 56.7 61.0 67.6 19.9 4 x 4 x 9/16 380 Hot rolled 42.56 5 400 30.6 5.097 30.7 48.1 50.5 53.0 57.1 61.4 68.0 19.8 5 x 3 1/2 x 1/2 350 Hot rolled 40.51 5 161 42.1 8.313 40.1 38.9 41.4 43.8 47.9 52.2 58.9 19.2 5 x 5 x 1/2 380 Hot rolled 48.25 6 129 36.4 9.365 39.1 58.0 60.3 62.6 66.6 70.7 77.1 25.0 5 x 5 x 9/16 380 Hot rolled 53.91 6 850 37.0 10.353 38.9 58.2 60.6 62.9 67.0 71.1 77.5 24.9 5 x 5 x 5/8 380 Hot rolled 59.57 7 561 37.6 11.300 38.7 58.5 60.9 63.3 67.3 71.4 77.9 24.8 6 x 6 x 9/16 380 Hot rolled 65.18 8 296 43.3 18.232 46.9 68.3 70.6 72.9 76.8 80.8 87.0 29.9 6 x 4 x 5/8 350 Hot rolled 59.57 7 561 51.6 17.539 48.2 43.5 45.9 48.3 52.4 56.6 63.2 21.9 6 x 6 x 5/8 380 Hot rolled 72.08 9 161 43.9 20.105 46.8 68.7 71.1 73.3 77.3 81.3 87.5 29.9 6 x 6 x 3/4 300 Hot rolled 85.48 10 887 45.1 23.438 46.4 69.3 71.6 74.0 77.9 82.0 88.3 29.8 8 x 8 x 3/4 300 Hot rolled 115.86 14 758 57.8 58.054 62.7 89.7 92.0 94.2 98.0 101.9 107.9 40.0 8 x 8 x 1 300 Hot rolled 151.90 19 355 60.1 74.075 61.9 90.8 93.1 95.4 99.3 103.2 109.3 39.7 9 Accessories
  9. 9. Material impErial Material (in.) Grade (ksi) Forming Mass (plf) Area (in.2 ) l (in.4 ) r (in.) 1/2 50 Hot rolled 0.67 0.20 0.003 0.13 9/16 50 Hot rolled 0.84 0.25 0.005 0.14 5/8 50 Hot rolled 1.04 0.31 0.007 0.16 11/16 50 Hot rolled 1.26 0.37 0.011 0.17 3/4 50 Hot rolled 1.50 0.44 0.016 0.19 13/16 50 Hot rolled 1.76 0.52 0.021 0.20 7/8 50 Hot rolled 2.05 0.60 0.029 0.22 15/16 50 Hot rolled 2.35 0.69 0.038 0.23 1 50 Hot rolled 2.67 0.79 0.049 0.25 1 1/8 50 Hot rolled 3.38 0.99 0.079 0.28 1 square 50 Hot rolled 3.40 1.00 0.083 0.29 Axis X-X Axis Y-Y Material Grade (ksi) Forming Mass (plf) Area (in.2) y (in.) lxx (in.4) rxx (in.) lyy (in.4) ryy (in.)(in.) (in.) (in.) 1 x 5/8 x 0.090 50 Cold formed 0.57 0.17 0.20 0.005 0.18 0.022 0.37 1 x 0.8 x 0.090 50 Cold formed 0.68 0.20 0.28 0.012 0.24 0.029 0.38 1 x 0.85 x 0.090 50 Cold formed 0.72 0.21 0.31 0.014 0.26 0.031 0.39 1 x 1 x 0.090 50 Cold formed 0.77 0.23 0.34 0.019 0.29 0.034 0.39 1 x 1 x 0.118 50 Cold formed 1.00 0.30 0.38 0.026 0.30 0.042 0.38 1 x 1.05 x 0.090 50 Cold formed 0.86 0.25 0.41 0.028 0.33 0.039 0.40 1 x 1.1 x 0.118 50 Cold formed 1.13 0.33 0.45 0.039 0.34 0.049 0.39 1 3/8 x 1.27 x 0.118 50 Cold formed 1.42 0.42 0.48 0.067 0.40 0.125 0.55 1 3/8 x 1 3/8 x 0.118 50 Cold formed 1.49 0.44 0.52 0.082 0.43 0.134 0.55 1 3/8 x 1 3/8 x 0.157 50 Cold formed 1.98 0.58 0.56 0.113 0.44 0.167 0.54 1 3/4 x 1 1/2 x 0.157 50 Cold formed 2.32 0.68 0.57 0.160 0.48 0.332 0.70 1 3/4 x 1 3/4 x 0.197 50 Cold formed 3.14 0.93 0.71 0.289 0.56 0.442 0.69 2 3/8 x 2 x 0.197 50 Cold formed 3.75 1.10 0.71 0.412 0.61 0.953 0.93 Round and square bars U shapes Section properties Axes convention XX Y Y XX Y Y y xx Y Y xx y y 10 Accessories
  10. 10. Double angles (long legs back-to-back) impErial Axis X-X ryy with different gaps Axis Z Material Grade (ksi) Forming Mass (plf) Area (in.2) y (in.) lxx (in.4) rxx (in.) 1/2 (in.) 3/4 (in.) 1 (in.) 1 3/8 (in.) 1 3/4 (in.) 2 3/8 (in.) rz (in.)(in.)www (in.) (in.) 1 x 1 x 0.090 55 Cold formed 1.17 0.33 0.29 0.031 0.31 0.62 0.73 0.84 1.03 1.22 1.50 0.19 1 x 1 x 7/64 55 Hot rolled 1.40 0.41 0.29 0.039 0.31 0.62 0.73 0.84 1.03 1.22 1.50 0.20 1 x 1 x 0.118 55 Cold formed 1.49 0.43 0.31 0.040 0.31 0.64 0.75 0.86 1.04 1.23 1.52 0.19 1 x 1 x 1/8 55 Hot rolled 1.60 0.46 0.30 0.043 0.30 0.63 0.74 0.84 1.03 1.22 1.51 0.20 1 1/8 x 1 1/8 x 0.090 55 Cold formed 1.32 0.38 0.32 0.046 0.35 0.67 0.78 0.89 1.07 1.26 1.54 0.22 1 1/8 x 1 1/8 x 0.118 55 Cold formed 1.70 0.49 0.34 0.059 0.35 0.68 0.79 0.90 1.08 1.27 1.56 0.22 1 1/4 x 1 1/4 x 0.118 55 Cold formed 1.91 0.54 0.37 0.082 0.39 0.73 0.84 0.94 1.13 1.31 1.60 0.24 1 1/4 x 1 1/4 x 1/8 55 Hot rolled 2.02 0.60 0.36 0.088 0.38 0.72 0.83 0.93 1.12 1.30 1.59 0.25 1 1/4 x 1 1/4 x 3/16 55 Hot rolled 2.96 0.86 0.38 0.123 0.38 0.73 0.84 0.95 1.13 1.32 1.61 0.24 1 3/8 x 1 3/8 x 0.118 55 Cold formed 2.11 0.60 0.40 0.111 0.43 0.78 0.88 0.99 1.17 1.35 1.64 0.27 1 1/2 x 1 1/2 x 0.118 55 Cold formed 2.32 0.66 0.43 0.145 0.47 0.83 0.93 1.03 1.21 1.40 1.68 0.29 1 1/2 x 1 1/2 x 1/8 55 Hot rolled 2.46 0.72 0.42 0.156 0.47 0.82 0.92 1.02 1.20 1.39 1.67 0.30 1 1/2 x 1 1/2 x 5/32 55 Hot rolled 3.02 0.89 0.43 0.189 0.46 0.82 0.93 1.03 1.21 1.40 1.68 0.29 1 1/2 x 1 1/2 x 0.157 55 Cold formed 3.00 0.86 0.45 0.185 0.46 0.84 0.94 1.05 1.23 1.41 1.70 0.29 1 1/2 x 1 1/2 x 3/16 55 Hot rolled 3.60 1.06 0.44 0.220 0.46 0.83 0.94 1.04 1.22 1.41 1.69 0.29 1 5/8 x 1 5/8 x 0.118 55 Cold formed 2.52 0.72 0.46 0.187 0.51 0.87 0.98 1.08 1.26 1.44 1.72 0.32 1 5/8 x 1 5/8 x 0.157 55 Cold formed 3.28 0.94 0.48 0.239 0.50 0.89 0.99 1.10 1.27 1.46 1.74 0.31 1 3/4 x 1 3/4 x 0.118 55 Cold formed 2.73 0.78 0.49 0.236 0.55 0.92 1.03 1.13 1.30 1.48 1.76 0.34 1 3/4 x 1 3/4 x 5/32 55 Hot rolled 3.57 1.04 0.50 0.307 0.54 0.92 1.02 1.13 1.30 1.48 1.76 0.35 1 3/4 x 1 3/4 x 0.157 55 Cold formed 3.55 1.02 0.51 0.302 0.54 0.94 1.04 1.14 1.32 1.50 1.78 0.34 1 3/4 x 1 3/4 x 3/16 55 Hot rolled 4.24 1.24 0.51 0.358 0.54 0.93 1.03 1.13 1.31 1.49 1.77 0.34 1 7/8 x 1 7/8 x 0.157 55 Cold formed 3.82 1.10 0.54 0.375 0.58 0.98 1.09 1.19 1.36 1.54 1.82 0.36 1 7/8 x 1 7/8 x 0.197 55 Cold formed 4.68 1.35 0.56 0.452 0.58 1.00 1.10 1.20 1.38 1.56 1.84 0.36 2 x 2 x 0.118 55 Cold formed 3.13 0.90 0.56 0.357 0.63 1.02 1.12 1.22 1.39 1.57 1.85 0.39 2 x 2 x 0.157 55 Cold formed 4.10 1.18 0.57 0.460 0.62 1.03 1.14 1.24 1.41 1.59 1.86 0.39 2 x 2 x 3/16 55 Hot rolled 4.88 1.42 0.57 0.545 0.62 1.03 1.13 1.23 1.40 1.58 1.86 0.39 2 x 2 x 0.197 55 Cold formed 5.02 1.45 0.59 0.555 0.62 1.05 1.15 1.25 1.42 1.60 1.88 0.39 2 x 2 x 7/32 55 Hot rolled 5.62 1.66 0.58 0.622 0.61 1.03 1.13 1.24 1.41 1.59 1.87 0.39 2 x 2 x 1/4 55 Hot rolled 6.38 1.88 0.59 0.695 0.61 1.04 1.14 1.24 1.42 1.60 1.87 0.39 2 1/8 x 2 1/8 x 0.157 55 Cold formed 4.37 1.26 0.61 0.556 0.66 1.08 1.18 1.28 1.45 1.63 1.91 0.42 2 1/8 x 2 1/8 x 0.197 55 Cold formed 5.36 1.55 0.62 0.672 0.66 1.09 1.20 1.30 1.47 1.65 1.92 0.41 2 1/8 x 2 1/8 x 0.236 55 Cold formed 6.31 1.831 0.64 0.781 0.65 1.09 1.20 1.30 1.47 1.65 1.93 0.41 2 1/4 x 2 1/4 x 0.197 55 Cold formed 5.70 1.64 0.66 0.806 0.70 1.14 1.24 1.34 1.52 1.69 1.96 0.44 2 1/4 x 2 1/4 x 0.236 55 Cold formed 6.72 1.94 0.67 0.937 0.69 1.16 1.26 1.36 1.53 1.71 1.98 0.43 2 3/8 x 2 3/8 x 0.197 55 Cold formed 6.04 1.74 0.69 0.955 0.74 1.19 1.29 1.39 1.56 1.74 2.01 0.46 2 3/8 x 2 3/8 x 0.236 55 Cold formed 7.12 2.06 0.71 1.113 0.73 1.21 1.31 1.40 1.58 1.75 2.02 0.46 2 1/2 x 2 1/2 x 0.197 55 Cold formed 6.38 1.84 0.72 1.122 0.78 1.24 1.34 1.44 1.61 1.78 2.05 0.49 2 1/2 x 2 1/2 x 0.236 55 Cold formed 7.53 2.18 0.74 1.310 0.77 1.25 1.35 1.45 1.62 1.80 2.07 0.48 2 1/2 x 2 1/2 x 1/4 55 Hot rolled 8.21 2.38 0.72 1.406 0.77 1.24 1.34 1.43 1.60 1.78 2.05 0.49 2 1/2 x 2 1/2 x 5/16 55 Hot rolled 10.00 2.93 0.74 1.697 0.76 1.25 1.35 1.45 1.62 1.79 2.07 0.49 2 5/8 x 2 5/8 x 0.236 55 Cold formed 7.94 2.30 0.77 1.529 0.81 1.30 1.40 1.50 1.67 1.84 2.11 0.51 2 3/4 x 2 3/4 x 0.236 55 Cold formed 8.34 2.42 0.80 1.771 0.86 1.35 1.45 1.55 1.72 1.89 2.16 0.53 2 7/8 x 2 7/8 x 0.236 55 Cold formed 8.75 2.53 0.83 2.037 0.90 1.40 1.50 1.60 1.76 1.94 2.20 0.56 3 x 3 x 0.236 55 Cold formed 9.16 2.65 0.86 2.328 0.94 1.45 1.55 1.65 1.81 1.98 2.25 0.58 3 x 2 x 5/16 50 Hot rolled 10.01 2.92 1.02 2.632 0.95 0.95 1.06 1.16 1.33 1.51 1.79 0.43 3 x 3 x 5/16 55 Hot rolled 12.20 3.55 0.86 3.017 0.92 1.45 1.54 1.64 1.81 1.98 2.24 0.59 3 x 3 x 3/8 55 Hot rolled 14.41 4.22 0.89 3.519 0.91 1.46 1.56 1.65 1.82 1.99 2.26 0.59 3 1/8 x 3 1/8 x 0.236 55 Cold formed 9.56 2.77 0.89 2.646 0.98 1.50 1.60 1.69 1.86 2.03 2.29 0.61 3 1/2 x 3 1/2 x 3/8 55 Hot rolled 17.00 4.97 1.01 5.728 1.07 1.66 1.75 1.85 2.01 2.18 2.44 0.69 4 x 3 x 3/8 55 Hot rolled 17.01 4.96 1.28 7.924 1.26 1.36 1.45 1.55 1.71 1.89 2.15 0.64 4 x 4 x 3/8 55 Hot rolled 19.62 5.72 1.14 8.721 1.23 1.86 1.95 2.05 2.21 2.37 2.63 0.79 4 x 3 x 1/2 55 Hot rolled 22.21 6.50 1.33 10.097 1.25 1.38 1.48 1.58 1.74 1.92 2.19 0.64 4 x 4 x 1/2 55 Hot rolled 25.62 7.53 1.18 11.123 1.22 1.88 1.98 2.07 2.23 2.40 2.66 0.78 4 x 4 x 9/16 55 Hot rolled 28.60 8.37 1.21 12.246 1.21 1.89 1.99 2.08 2.25 2.42 2.68 0.78 5 x 3 1/2 x 1/2 50 Hot rolled 27.22 8.00 1.66 19.971 1.58 1.53 1.63 1.72 1.89 2.06 2.32 0.75 5 x 5 x 1/2 55 Hot rolled 32.42 9.50 1.43 22.501 1.54 2.28 2.37 2.47 2.62 2.78 3.03 0.98 5 x 5 x 9/16 55 Hot rolled 36.23 10.62 1.46 24.874 1.53 2.29 2.39 2.48 2.64 2.80 3.05 0.98 5 x 5 x 5/8 55 Hot rolled 40.03 11.72 1.48 27.148 1.52 2.30 2.40 2.49 2.65 2.81 3.06 0.98 6 x 6 x 9/16 55 Hot rolled 43.80 12.86 1.70 43.802 1.85 2.69 2.78 2.87 3.02 3.18 3.43 1.18 6 x 4 x 5/8 50 Hot rolled 40.03 11.72 2.03 42.139 1.90 1.71 1.81 1.90 2.06 2.23 2.49 0.86 6 x 6 x 5/8 55 Hot rolled 48.44 14.20 1.73 48.302 1.84 2.71 2.80 2.89 3.04 3.20 3.45 1.18 6 x 6 x 3/4 44 Hot rolled 57.44 16.87 1.78 56.310 1.83 2.73 2.82 2.91 3.07 3.23 3.47 1.17 8 x 8 x 3/4 44 Hot rolled 77.85 22.87 2.28 139.480 2.47 3.53 3.62 3.71 3.86 4.01 4.25 1.58 8 x 8 x 1 44 Hot rolled 102.07 30.00 2.37 177.970 2.44 3.57 3.67 3.76 3.91 4.06 4.30 1.56 11 Accessories
  11. 11. Bombardier Centre  I  La Pocatière, Quebec Alphonse-Desjardins Sports Complex I Trois-Rivières, Quebec Athletic Facility  I  Terrebonne, Quebec 12 Accessories
  12. 12. Bridging Specifications The CAN/CSA S16-01 standard specifies a bridging system to assure steel joist stability. Some important points to consider are: • Maximum slenderness ratio by bridging type; • Minimum capacity of the bridging system; • Service load criteria; • Maximum unsupported lengths for the top and bottom chords of the joist; • Erection criteria; • Bridging system requirements for special support conditions. The two types of bridging used and their maximum unsupported length are as follows: • Horizontal bridging 300 x rz • Diagonal bridging 200 x rz The horizontal bridging type is most commonly used to stabilize joists. Attachment of diagonal and horizontal bridging to joist chords with a minimum capacity of 3kN is in accordance with clause 16.7.6 of CSA S16-01. The selection tables for horizontal and diagonal bridging angles presented herein meet the slenderness and minimum capacity criteria. The bridging system performs two main functions: • To assure joist stability during erection by providing lateral support to the top and bottom chords of the joists; • To hold the joists in the position shown on the drawings, normally vertical. In general, the bridging must be spaced along the chords so that the laterally unsupported distance does not exceed: • Top chord 170 x ryy • Bottom chord 240 x ryy For safety reasons, a line of cross bridging is recommended for joists having a span longer than 12.2 m (about 40 ft.). No construction loads shall be placed on the joists until the bridging system is completely installed. Once installed, the steel deck generally offers sufficient rigidity to provide the lateral stability to the top chord. The resistance of decking and joints must be verified by the joist designer to ensure that adequate lateral support is provided to the top chord. For the bottom chord, bridging must be designed with the maximum slenderness ratio criterion of this tension member. If the bottom chord is subject to compression loads, due to uplift forces or other compression causing forces, a system with more bridging lines must be used. If uplift forces are applied to the joist, a line of bridging is required at the first bottom chord panel point at both  ends of the joist. The length of horizontal bridging supplied by Canam is based on a maximum lap of 150 mm (6 in.). The ends of the bridging system on a beam or masonry wall must comply with clause 16.7.7 of the CAN/CSA S16-01 standard. Certain joist loading conditions require special bracing systems. Note that this reference is to bracing rather than bridging. Members supplied in these cases must meet the criteria of clause 9.2 of CAN/CSA S16-01. Two such cases are cantilever joists and perimeter joists that laterally support the top of wind columns. 13 Accessories
  13. 13. Bridging line requirements The following tables are a guide to evaluate the number of top and bottom chord bridging lines for a joist having a uniformly distributed load. The number of lines is based upon the maximum allowable spacing between the lines at the top chord. This number can vary with chord angle separation and chord sizes. As previously mentioned, when uplift forces are applied to the joist, additional bridging lines are required near both ends of the bottom chord. MEtriC Span (m) Factored load (kN/m) Service load (kN/m) 4.5 6.0 7.5 9.0 10.5 12.0 13.5 15.0 16.5 18.0 19.5 21.0 22.5 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 4 1 1 1 1 1 1 1 1 1 1 1 1 1 5 1 1 1 1 1 1 1 1 1 1 1 1 1 6 1 1 1 1 1 1 1 1 1 1 1 1 1 7 2 2 1 1 1 1 1 1 1 1 1 1 1 8 2 2 2 1 1 1 1 1 1 1 1 1 1 9 2 2 2 2 1 1 1 1 1 1 1 1 1 10 2 2 2 2 1 1 1 1 1 1 1 1 1 11 2 2 2 2 2 2 2 2 1 1 1 1 1 12 2 2 2 2 2 2 2 2 2 2 2 1 1 13 2 2 2 2 2 2 2 2 2 2 2 2 2 14 2 2 2 2 2 2 2 2 2 2 2 2 2 15 3 3 2 2 2 2 2 2 2 2 2 2 2 4.5 5.4 6.3 7.2 8.1 9.0 9.9 10.8 11.7 12.6 13.5 14.4 15.3 3.0 3.6 4.2 4.8 5.4 6.0 6.6 7.2 7.8 8.4 9.0 9.6 10.2 16 3 3 3 2 2 2 2 2 2 2 2 2 2 17 3 3 3 3 3 2 2 2 2 2 2 2 2 18 3 3 3 3 3 2 2 2 2 2 2 2 2 19 3 3 3 3 3 3 3 2 2 2 2 2 2 20 3 3 3 3 3 3 3 2 2 2 2 2 2 22 4 3 3 3 3 3 3 3 3 2 2 2 2 24 4 3 3 3 3 3 3 3 3 3 2 2 2 26 4 3 3 3 3 3 3 3 3 3 3 3 3 28 4 3 3 3 3 3 3 3 3 3 3 3 3 30 4 3 3 3 3 3 3 3 3 3 3 3 3 34 4 3 3 3 3 3 3 3 3 3 3 3 3 38 4 4 4 4 4 4 4 4 3 3 3 3 3 42 4 4 4 4 4 4 4 4 4 4 4 3 3 46 4 4 4 4 4 4 4 4 4 4 4 3 3 Table for selecting the number of bridging lines Legend 0 line 2 lines 4 lines 1 line 3 lines 14 Accessories
  14. 14. impErial Span (ft.) Factored load (plf) Service load (plf) 300 405 510 615 720 825 930 1,035 1,140 1,245 1,350 1,455 1,560 200 270 340 410 480 550 620 690 760 830 900 970 1,040 10 0 0 0 0 0 0 0 0 0 0 0 0 0 13 1 1 1 1 1 1 1 1 1 1 1 1 1 16 1 1 1 1 1 1 1 1 1 1 1 1 1 20 1 1 1 1 1 1 1 1 1 1 1 1 1 23 2 2 1 1 1 1 1 1 1 1 1 1 1 26 2 2 2 1 1 1 1 1 1 1 1 1 1 30 2 2 2 2 1 1 1 1 1 1 1 1 1 33 2 2 2 2 1 1 1 1 1 1 1 1 1 36 2 2 2 2 2 2 2 2 1 1 1 1 1 40 2 2 2 2 2 2 2 2 2 2 2 1 1 43 2 2 2 2 2 2 2 2 2 2 2 2 2 46 2 2 2 2 2 2 2 2 2 2 2 2 2 49 3 3 2 2 2 2 2 2 2 2 2 2 2 300 360 420 480 540 600 660 720 780 840 900 960 1,020 200 240 280 320 360 400 440 480 520 560 600 640 680 52 3 3 3 2 2 2 2 2 2 2 2 2 2 56 3 3 3 3 3 2 2 2 2 2 2 2 2 59 3 3 3 3 3 2 2 2 2 2 2 2 2 62 3 3 3 3 3 3 3 2 2 2 2 2 2 65 3 3 3 3 3 3 3 2 2 2 2 2 2 72 4 3 3 3 3 3 3 3 3 2 2 2 2 79 4 3 3 3 3 3 3 3 3 3 2 2 2 85 4 3 3 3 3 3 3 3 3 3 3 3 3 92 4 3 3 3 3 3 3 3 3 3 3 3 3 98 4 3 3 3 3 3 3 3 3 3 3 3 3 112 4 3 3 3 3 3 3 3 3 3 3 3 3 125 4 4 4 4 4 4 4 4 3 3 3 3 3 138 4 4 4 4 4 4 4 4 4 4 4 3 3 151 4 4 4 4 4 4 4 4 4 4 4 3 3 Table for selecting the number of bridging lines Legend 0 line 2 lines 4 lines 1 line 3 lines 15 Accessories
  15. 15. Spacing for bridging Maximum joist spacing (mm) for horizontal bridging Maximum joist spacing (mm) for diagonal bridging * To use with welded diagonal bridging or bolted diagonal bridging with maximum 10 mm (3/8 in.) bolt diameter. Note: The diagonal bridging must be tied at mid-length. Bridging angle size L 1 1/4 x 1 1/4 x 0.090 L 1 1/2 x 1 1/2 x 0.090 L 1 5/8 x 0.118 L 1 3/4 x 1 3/4 x 0.118 L 2 x 2 x 1/8 L 1 1/2 x 1 1/2 x 0.118 L 1 3/4 x 1 3/4 x 1/8 L 2 x 2 x 0.157 1,720 2,240 2,420 2,620 2,970 Joist depth (mm) Bridging angle size L 1 1/4 x 1 1/4 x 0.090* L 1 1/2 x 1 1/2 x 0.090 L 1 5/8 x 0.118 L 1 3/4 x 1 3/4 x 0.118 L 2 x 2 x 1/8 L 1 1/2 x 1 1/2 x 0.118 L 1 3/4 x 1 3/4 x 1/8 L 2 x 2 x 0.157   300 2,420 2,980 3,220 3,490 3,950   350 2,420 2,970 3,220 3,480 3,950   400 2,410 2,960 3,210 3,480 3,950   450 2,400 2,960 3,200 3,470 3,940   500 2,390 2,950 3,190 3,460 3,930   550 2,380 2,940 3,190 3,450 3,930   600 2,370 2,930 3,180 3,450 3,920   650 2,350 2,920 3,170 3,440 3,910   700 2,340 2,910 3,160 3,430 3,900   750 2,320 2,890 3,140 3,420 3,890   800 2,300 2,880 3,130 3,400 3,880   900 2,270 2,850 3,100 3,380 3,860 1,000 2,220 2,810 3,070 3,350 3,830 1,100 2,170 2,770 3,040 3,320 3,810 1,200 2,120 2,730 3,000 3,280 3,770 1,300 2,680 2,950 3,240 3,740 1,400 2,630 2,910 3,200 3,700 1,500 2,570 2,850 3,150 3,660 1,600 2,510 2,800 3,100 3,620 1,700 2,440 2,740 3,040 3,570 1,800 2,370 2,670 2,980 3,520 MEtriC 16 Accessories
  16. 16. Maximum joist spacing (ft.) For horizontal bridging Maximum joist spacing (ft.) For diagonal bridging * To use with welded diagonal bridging or bolted diagonal bridging with maximum 10 mm (3/8 in.) bolt diameter. Note: The diagonal bridging must be tied at mid-length. Bridging angle size L 1 1/4 x 1 1/4 x 0.090 L 1 1/2 x 1 1/2 x 0.090 L 1 5/8 x 0.118 L 1 3/4 x 1 3/4 x 0.118 L 2 x 2 x 1/8 L 1 1/2 x 1 1/2 x 0.118 L 1 3/4 x 1 3/4 x 1/8 L 2 x 2 x 0.157 5’ - 7” 7’ - 4” 7’ - 11” 8’ - 7” 9’ - 9” Joist depth (in.) Bridging angle size L 1 1/4 x 1 1/4 x 0.090* L 1 1/2 x 1 1/2 x 0.090 L 1 5/8 x 0.118 L 1 3/4 x 1 3/4 x 0.118 L 2 x 2 x 1/8 L 1 1/2 x 1 1/2 x 0.118 L 1 3/4 x 1 3/4 x 1/8 L 2 x 2 x 0.157 12 7’ - 11’’ 9’ - 9’’ 10’ - 6’’ 11’ - 5’’ 12’ - 11’’ 14 7’ - 11’’ 9’ - 8’ 10’ - 6’’ 11’ - 5’’ 12’ - 11’’ 16 7’ - 10’’ 9’ - 8’’ 10’ - 6’’ 11’ - 4’’ 12’ - 11’’ 18 7’ - 10’’ 9’ - 8’’ 10’ - 6’’ 11’ - 4’’ 12’ - 11’’ 20 7’ - 10’’ 9’ - 8’’ 10’ - 5’’ 11’ - 4’’ 12’ - 10’’ 22 7’ - 9’’ 9’ - 7’’ 10’ - 5’’ 11’ - 3’’ 12’ - 10’’ 24 7’ - 9’’ 9’ - 7’’ 10’ - 5’’ 11’ - 3’’ 12’ - 10’’ 26 7’ - 8’’ 9’ - 6’’ 10’ - 4’’ 11’ - 3’’ 12’ - 9’’ 28 7’ - 8’’ 9’ - 6’’ 10’ - 4’’ 11’ - 2’’ 12’ - 9’’ 30 7’ - 7’’ 9’ - 5’’ 10’ - 3’’ 11’ - 2’’ 12’ - 9’’ 32 7’ - 6’’ 9’ - 5’’ 10’ - 3’’ 11’ - 1’’ 12’ - 8’’ 36 7’ - 5’’ 9’ - 4’’ 10’ - 2’’ 11’ - 0’’ 12’ - 7’’ 40 7’ - 3’’ 9’ - 2’’ 10’ - 0’’ 10’ - 11’’ 12’ - 6’’ 44 7’ - 1’’ 9’ - 1’’ 9’ - 11’’ 10’ - 10’’ 12’ - 5’’ 48 6’ - 11’’ 8’ - 11’’ 9’ - 9’’ 10’ - 9’’ 12’ - 4’’ 52 8’ - 9’’ 9’ - 8’’ 10’ - 7’’ 12’ - 3’’ 56 8’ - 7’’ 9’ - 6’’ 10’ - 5’’ 12’ - 1’’ 60 8’ - 5’’ 9’ - 4’’ 10’ - 4’’ 12’ - 0’’ 64 8’ - 2’’ 9’ - 2’’ 10’ - 2’’ 11’ - 10’’ 68 8’ - 0’’ 8’ - 11’’ 9’ - 11’’ 11’ - 8’’ 72 7’ - 9’’ 8’ - 9’’ 9’ - 9’’ 11’ - 6’’ impErial 17 Accessories
  17. 17. Knee braces To provide lateral support to the bottom chord of the joist girders, knee bracing is used. These knee braces are installed into position where required at joist support locations and generally on both sides of the joist girder. They join the top chord of the joist girder to the bottom chord of the joist as illustrated below. A knee brace selection table is provided based on a maximum allowable slenderness ratio of 200 x rz. In some cases, installation of knee braces can be avoided by extending the bottom chord length of some joists when the joist girder depth is similar to that of the joist that it supports. When a joist girder is used to support girts instead of joists, the knee brace system may not be recommended. Usually for girt shapes we use cross braces tied at mid- length as lateral support to the joist girder when the spacing between joist girders (girts span) is less than 6,000 mm (20 ft.), or when the girt section thickness is smaller than 2.3 mm (3/32 in.). In all other cases, the standard knee brace system may be used. The building designer should take into consideration that the knee brace stabilizing the bottom chord of the joist girder induces loads on the girts at the connection points. Maximum knee brace length l (mm) Maximum knee brace length l (ft.) Brace angle size L 1 1/2 x 1 1/2 x 0.157 L 2 x 2 x 0.157 L 2 1/2 x 2 1/2 x 3/16 L 3 x 3 x 0.236 L 1 1/2 x 1 1/2 x 5/32 L 2 x 2 x 5/32 L 2 1/2 x 2 1/2 x 0.197 L 3 x 3 x 1/4 L 1 1/2 x 1 1/2 x 3/16 L 2 x 2 x 3/16 L 2 1/2 x 2 1/2 x 1/4 L 3 x 3 x 5/16 1,470 1,990 2,480 2,980 Brace angle size L 1 1/2 x 1 1/2 x 0.157 L 2 x 2 x 0.157 L 2 1/2 x 2 1/2 x 3/16 L 3 x 3 x 0.236 L 1 1/2 x 1 1/2 x 5/32 L 2 x 2 x 5/32 L 2 1/2 x 2 1/2 x 0.197 L 3 x 3 x 1/4 L 1 1/2 x 1 1/2 x 3/16 L 2 x 2 x 3/16 L 2 1/2 x 2 1/2 x 1/4 L 3 x 3 x 5/16 4’ - 10” 6’ - 6” 8’ - 2” 9’ - 9” MEtriC impErial Joist TYP. Joist girder By Canam Joist APPROX. 45° Knee braces - detail 2 Joist Joist girder Joist Knee braces - detail 3 Joist Joist girder TYP. By Canam Joist Knee braces - detail 1 18 Accessories
  18. 18. Material weights The tables below can be used as a guide to establish in which direction the joists should be orientated compared to the joist girders for a particular bay area and various total uniform factored loads. They are also a guide for the building designer to evaluate the dead load of joists and joist girders to be used for design. Estimated self-weight of joists and joist girders (kPa) Estimated self-weight of joists and joist girders (psf) MEtriC imperial Bay area (m2 ) Joist/Joist girder Span ratio Factored uniform load (kPa) Joist (m) J.G. (m) 2 3 4 5 6 7 8 9 10 50 0.5 0.09 0.11 0.13 0.14 0.17 0.20 0.23 0.25 0.28 5.0 10.0 50 1 0.08 0.09 0.10 0.13 0.16 0.18 0.21 0.24 0.26 7.1 7.1 50 2 0.07 0.08 0.11 0.14 0.16 0.19 0.22 0.25 0.27 10.0 5.0 100 0.5 0.10 0.12 0.15 0.19 0.22 0.26 0.30 0.34 0.37 7.1 14.1 100 1 0.08 0.10 0.14 0.17 0.21 0.24 0.28 0.31 0.35 10.0 10.0 100 2 0.07 0.11 0.14 0.18 0.22 0.25 0.29 0.33 0.36 14.1 7.1 150 0.5 0.11 0.14 0.18 0.23 0.27 0.32 0.37 0.41 0.46 8.7 17.3 150 1 0.09 0.13 0.17 0.21 0.25 0.30 0.34 0.38 0.42 12.2 12.2 150 2 0.09 0.13 0.18 0.22 0.27 0.31 0.35 0.40 0.44 17.3 8.7 200 0.5 0.12 0.16 0.21 0.26 0.32 0.37 0.42 0.48 0.53 10.0 20.0 200 1 0.10 0.15 0.20 0.25 0.29 0.34 0.39 0.44 0.49 14.1 14.1 200 2 0.10 0.15 0.20 0.26 0.31 0.36 0.41 0.46 0.51 20.0 10.0 250 0.5 0.13 0.18 0.24 0.30 0.35 0.41 0.47 0.53 0.59 11.2 22.4 250 1 0.11 0.16 0.22 0.27 0.33 0.38 0.44 0.49 0.55 15.8 15.8 250 2 0.11 0.17 0.23 0.29 0.34 0.40 0.46 0.51 0.57 22.4 11.2 300 0.5 0.13 0.19 0.26 0.32 0.39 0.45 0.52 0.58 0.65 12.2 24.5 300 1 0.12 0.18 0.24 0.30 0.36 0.42 0.48 0.54 0.60 17.3 17.3 300 2 0.13 0.19 0.25 0.31 0.38 0.44 0.50 0.56 0.63 24.5 12.2 Bay area (ft.2 ) Joist/Joist girder Span ratio Factored uniform load (psf) Joist (ft.) J.G. (ft.) 42 63 83 104 125 146 167 188 209 500 1/2 2.0 2.6 3.1 3.6  4.2  4.9  5.6  6.3  7.0 15.8 31.6 500 1 1.7 2.1 2.5 3.0  3.7  4.3  4.9  5.5  6.1 22.4 22.4 500 2 1.5 1.8 2.4 3.0  3.6  4.2  4.8  5.4  6.0 31.6 15.8 1,100 1/2 2.4 3.2 3.9 4.9  5.8  6.8  7.8  8.8  9.8 23.5 46.9 1,100 1 2.0 2.6 3.4 4.2  5.1  6.0  6.8  7.7  8.5 33.2 33.2 1,100 2 1.7 2.5 3.3 4.1  5.0  5.8  6.6  7.5  8.3 46.9 23.5 1,600 1/2 2.7 3.6 4.7 5.9  7.1  8.2  9.4 10.6 11.8 28.3 56.6 1,600 1 2.2 3.1 4.1 5.1  6.1  7.2  8.2  9.2 10.3 40.0 40.0 1,600 2 2.0 3.0 4.0 5.0  6.0  7.0  8.0  9.0 10.0 56.6 28.3 2,200 1/2 3.0 4.2 5.5 6.9  8.3  9.7 11.0 12.4 13.8 33.2 66.3 2,200 1 2.4 3.6 4.8 6.0  7.2  8.4  9.6 10.8 12.1 46.9 46.9 2,200 2 2.4 3.5 4.7 5.8  7.0  8.2  9.4 10.6 11.7 66.3 33.2 2,700 1/2 3.3 4.6 6.1 7.6  9.2 10.7 12.2 13.8 15.3 36.7 73.5 2,700 1 2.7 4.0 5.3 6.6  8.0  9.3 10.7 12.0 13.4 52.0 52.0 2,700 2 2.6 3.9 5.2 6.5  7.8  9.1 10.4 11.7 13.0 73.5 36.7 3,200 1/2 3.5 5.0 6.6 8.3 10.0 11.6 13.3 15.0 16.7 40.0 80.0 3,200 1 2.9 4.4 5.8 7.2  8.7 10.2 11.6 13.1 14.5 56.6 56.6 3,200 2 2.8 4.3 5.6 7.0  8.5  9.9 11.3 12.7 14.2 80.0 40.0 19 Accessories
  19. 19. Mass/wwces to use for design (Using normal density concrete) The weight of the main materials included in a floor or roof system is reproduced below. The density of certain materials is also indicated. This table allows the designer to quickly evaluate the dead and live loads to specify on drawings and specifications. kg/m3 kN/m3 Material pcf 7,850 77.0 Steel 490 2,640 25.9 Aluminum 165 2,580 25.3 Glass (plate) 161 2,400 23.5 Concrete (stone, reinforced) 150 2,000 19.6 Brick (common) 125 801 7.9 Wood (hard or treated) maximum 50 352 3.5 Wood (soft or dry) minimum 22 1,000 9.8 Water (fresh, 4°C) 62 897 8.8 Ice 56 641 6.3 Snow (wet) maximum 40 400 3.9 Snow (dry, packed) maximum 25 128 1.3 Snow (dry, fresh fallen) 8 1,100 10.8 Paint (52% of weight solids) 69 929 9.1 Oils 58 785 7.7 Alcohol 49 673 6.6 Gasoline 42 1,920 18.8 Sand and gravel (wet) 120 kg/m2 kN/m2 Material psf 10.1 0.10 Steel deck P-3615 (up to 0.91 mm) 2.1 16.3 0.16 Steel deck P-3615 (1.21 to 1.52 mm) 3.3 14.0 0.14 Steel deck P-2436 (up to 0.91 mm) 2.9 22.7 0.22 Steel deck P-2436 (1.21 to 1.52 mm) 4.8 193.7 1.90 Steel deck P-3615 composite (100 mm total slab) 39.7 313.0 3.07 Steel deck P-3615 composite (150 mm total slab) 64.3 259.0 2.54 Steel deck P-2432 composite (140 mm total slab) 53.5 402.7 3.95 Steel deck P-2432 composite (200 mm total slab) 82.9 15.3 0.15 Roofing 3 ply asphalt (no gravel) 3.1 5.1 0.05 Fiberglass insulation (batts 100 mm) 1.0 4.1 0.04 Fiberglass insulation (blown 100 mm) 0.8 7.1 0.07 Fiberglass insulation (rigid 100 mm) 1.5 3.1 0.03 Urethane (rigid foam 100 mm) 0.6 6.1 0.06 Insulating concrete (100 mm) 1.3 13.3 0.13 Gypsum wallboard (16 mm) 2.7 7.1 0.07 Sprayed fire protection (average) 1.5 25.5 0.25 Ducts, pipes, and wiring (average) 5.0 40.8 0.40 Plaster on lath/furring (20 mm) 8.4 265.1 2.60 Tiled ceiling with suspension and fixtures (average) 54.3 356.9 3.50 Hollow core precast (200 mm N.D. no topping) 73.1 14.3 0.14 Hollow core precast (300 mm N.D. no topping) 2.9 12.2 0.12 Plywood or chipboard (20 mm) 2.5 16.3 0.16 Hardwood floor (20 mm) 3.3 10.2 0.10 Wood joists 38 mm x 286 mm (400 mm c/c) 2.1 81.6 0.80 Carpeting 16.7 20.4 0.20 Ceramic (20 mm) on Mortar bed (12 mm) 4.2 178.4 1.75 Hollow concrete block 150 mm thick (cells empty) 36.6 214.1 2.10 Hollow concrete block 200 mm thick (cells empty) 43.9 295.7 2.90 Hollow concrete block 300 mm thick (cells empty) 60.6 221.8 2.18 Hollow concrete block 150 mm thick (1 of 4 cells filled) 45.4 277.8 2.73 Hollow concrete block 200 mm thick (1 of 4 cells filled) 56.9 397.6 3.90 Hollow concrete block 300 mm thick (1 of 4 cells filled) 81.5 20 Accessories
  20. 20. Extensions An extension designates a continuation beyond the normal bearing of the joist. The extension can be the top chord only or the full depth of the joist, in which case, it is referred to as a cantilever joist. The extended top chord section varies according to the following conditions: the design loads, the extension length, the deflection criterion, and the conditions of bearing and anchorage. The section can be reinforced if required. In a section without reinforcement, the extension material is the same as the top chord of the joist. A reinforced section has 2 or 4 angles as extension material, or 1 or 2 channels having a higher capacity than that of the top chord between the bearings. Also, a reinforced section projects into one or several interior panels such that the joist can resist bending and shearing forces brought on by the extension of the top chord. Top chord extension Variable Bearing Section reinforced with 2 angles A A B B C C Section A Section B Bearing Section C Section reinforced with 4 angles A A B B C C Bearing Section CSection A Section B Section reinforced with 1 channel A A B B C C Bearing Section B Section CSection A Section without reinforcement A A B B C C Section A Section B Section C Bearing Section reinforced with 2 channels A A B B C C Bearing Section CSection A Section B Cantilever joist Bearing Variable 21 Standard details
  21. 21. The tables below serve as a guide to determine a suitable shoe depth based on uniform loading and a maximum extension length. The extensions are based on the maximum capacity of a 2-channel section without any slope. This is an economical section for this kind of condition. The maximum top chord extension is determined by the bending and shear resistance of the section, or by the deflection of the extension, which is limited to L/120 with a fixed end. In fact, the joist and its extension are analyzed simultaneously in a matrix calculation. MetriC Maximum top chord extension (mm) Effective shoe depth (mm) Factored load (kN/m) Service load (kN/m) 4.5 6.0 7.5 9.0 10.5 12.0 13.5 15.0 16.5 18.0 19.5 21.0 22.5 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 100 1,920 1,750 1,620 1,520 1,450 1,380 1,330 1,290 1,240 1,200 1,150 1,130 1,100 125 2,390 2,170 2,010 1,900 1,800 1,700 1,650 1,550 1,500 1,450 1,400 1,350 1,300 150 2,750 2,500 2,350 2,200 2,050 1,950 1,900 1,800 1,750 1,650 1,600 1,550 1,550 175 3,050 2,800 2,600 2,450 2,300 2,200 2,150 2,050 2,000 1,900 1,850 1,800 1,750 200 3,300 3,000 2,800 2,650 2,550 2,450 2,350 2,250 2,200 2,100 2,050 2,000 1,950 imperial Maximum top chord extension (ft.) Effective shoe depth (in.) Factored load (lb./ft.) Service load (lb./ft.) 300 405 510 615 720 825 930 1035 1140 1245 1350 1455 1560 200 270 340 410 480 550 620 690 760 830 900 970 1040 4 6’ - 4” 5’ - 9” 5’ - 4” 5’ - 0” 4’ - 9” 4’ - 6” 4’ - 4” 4’ - 3” 4’ - 1” 3’ - 11” 3’ - 9” 3’ - 8” 3’ - 7” 5 7’ - 10” 7’ - 1” 6’ - 7” 6’ - 3” 5’ - 11” 5’ - 7” 5’ - 5” 5’ - 1” 4’ - 11” 4’ - 9” 4’ - 7” 4’ - 5” 4’ - 3” 6 9’ - 0” 8’ - 2” 7’ - 8” 7’ - 3” 6’ - 9” 6’ - 5” 6’ - 3”   5’ - 11” 5’ - 9” 5’ - 5” 5’ - 3” 5’ - 1” 5’ - 1” 7 10’ - 0” 9’ - 2” 8’ - 6” 8’ - 0” 7’ - 7” 7’ - 3” 7’ - 1” 6’ - 9” 6’ - 7” 6’ - 3” 6’ - 1”   5’ - 11” 5’ - 9” 8 10’ - 10” 9’ - 10” 9’ - 2” 8’ - 8” 8’ - 4” 8’ - 0” 7’ - 8” 7’ - 4” 7’ - 3” 6’ - 11” 6’ - 9” 6’ - 7” 6’ - 5” The building designer must make allowance for sufficient shoe depth when the top flange is not horizontal or in case of bolted assembly. In this case, the clear depth is less than the shoe depth. Clear depth Shoe depth 22 Standard details
  22. 22. ING of Canada  I  Saint-Hyacinthe, Quebec Maximum duct openings metric Dimensions of free openings for various joists and joist girder configurations Configuration (mm) Opening (mm) H P D S L R Joist Warren Geometry 200 250 110 95 70 150 250 250 150 120 90 182 300 305 190 150 110 232 350 305 220 175 120 258 ModifiedWarrenGeometry 400 610 240 220 140 410 450 610 320 265 200 420 500 610 360 290 220 454 550 610 390 315 240 484 600 610 420 340 250 512 650 610 440 350 260 526 700 610 460 375 270 550 750 610 490 395 280 572 800 610 510 410 290 592 900 610 550 440 310 622 1,000 610 580 465 320 646 1,100 650 630 505 340 694 1,200 700 690 555 380 762 1,300 800 750 605 410 838 1,500 900 880 705 480 972 Joist girder 750 600 430 345 240 500 900 600 500 400 280 564 1,050 600 560 450 300 616 1,200 600 610 490 330 658 1,350 600 650 530 340 694 1,500 600 680 560 360 726 Note: Final dimensions of free openings should be verified with Canam’s joist design sheet. When duct-opening dimensions exceed the limits above, some web members must be removed. The shear forces are then transferred to the adjacent web members of the top and bottom chords. The chords will need to be reinforced; this will limit the maximum height of the free opening as well. The maximum opening height should be limited to the joist depth minus 200 mm (8 in.). If the opening height cannot be limited to this value, contact Canam. Because the shear forces carried by the web members increase along the joist toward the bearing, the location of the duct opening is more critical near the bearings; more shear forces must be transferred to the top and bottom chords. For this reason, the duct-opening center must be located away from a bearing by a distance of at least 2.5 times the joist depth. The best location (for economical reasons) is at the mid span of the joist. D L R S S P 305 mm 12 in. H Warren Geometry; H Յ 350 mm (14 in.) D L RS S 610 mm (TYP) 24 in. (TYP) H Modified Warren Geometry; H Ն 400 mm (16 in.) Location must be greater than: 2.5 x H H 100 mm (4 in.) min. 100 mm (4 in.) min. Modified Warren Geometry Location must be greater than: 2.5 x H H 100 mm (4 in.) min. 100 mm (4 in.) min. Pratt Geometry 23 Standard details
  23. 23. Maximum duct openings imperial Dimensions of free openings for various joists and joist girder configurations Configuration (in.) Opening (in.) H P D S L R Joist 8 10  4.5  3.5 2.5 5.5 Warren Geometry 10 10  6.0  4.5 3.5 7.0 12 12  7.5  6.0 4.5 9.0 14 12  8.5  7.0 5.0 10.0 16 24  9.5  8.5 5.5 16.0 ModifiedWarrenGeometry 18 24 13.0 10.5 8.0 16.5 20 24 14.5 11.5 9.0 18.0 22 24 15.5 12.5 9.5 19.0 24 24 17.0 13.5 10.0 20.5 26 24 17.5 14.0 10.5 21.0 28 24 18.5 15.0 11.0 22.0 30 24 19.5 15.5 11.0 23.0 32 24 20.5 16.5 11.5 23.5 36 24 22.0 17.5 12.0 24.5 40 24 23.5 18.5 12.5 25.5 44 26 25.0 20.0 13.5 27.5 48 28 27.5 22.0 15.0 30.5 54 32 31.0 24.5 17.0 34.0 60 36 35.0 28.0 19.5 39.0 Joist girder 30 24 17.0 13.5 10.0 20.0 36 24 20.0 16.0 11.0 22.5 42 24 22.5 18.0 12.0 24.5 48 24 24.5 19.5 13.0 26.5 54 24 26.0 21.0 13.5 27.5 60 24 27.5 22.5 14.5 29.0 Note: Final dimensions of free openings should be verified with Canam’s joist design sheet. When duct-opening dimensions exceed the limits above, some web members must be removed. The shear forces are then transferred to the adjacent web members of the top and bottom chords. The chords will need to be reinforced; this will limit the maximum height of the free opening as well. The maximum opening height should be limited to the joist depth minus 200 mm (8 in.). If the opening height cannot be limited to this value, contact Canam. Because the shear forces carried by the web members increase along the joist toward the bearing, the location of the duct opening is more critical near the bearings; more shear forces must be transferred to the top and bottom chords. For this reason, the duct-opening center must be located away from a bearing by a distance of at least 2.5 times the joist depth. The best location (for economical reasons) is at the mid span of the joist. D L R S S P 305 mm 12 in. H Warren Geometry; H Յ 350 mm (14 in.) D L RS S 610 mm (TYP) 24 in. (TYP) H Modified Warren Geometry; H Ն 400 mm (16 in.) Location must be greater than: 2.5 x H H 100 mm (4 in.) min. 100 mm (4 in.) min. Modified Warren Geometry Location must be greater than: 2.5 x H H 100 mm (4 in.) min. 100 mm (4 in.) min. Pratt Geometry 24 Standard details
  24. 24. Avon Canada I Pointe-Claire, Quebec Agora, Collège Saint-Sacrement I Terrebonne, QuebecTransAlta Rainforest I Calgary, Alberta 25 Standard details
  25. 25. Geometry and shapes The geometry refers to the web profile system. The standard geometry types are presented below: In some cases, a joist could have 2 geometrical types. For architectural considerations, the building designer can specify a fixed geometry applicable to a joist group. More than one geometrical type may be specified. However, panel alignment of joists having varying lengths and loading conditions may not be possible. Joists are usually evenly spaced along a joist girder which can combine two types of geometry as shown below where a Warren type is combined with a modified Warren geometry. The panel points of a joist girder are usually located where joists are bearing. Depending on the joist spacing, the design engineer can add intermediate panel points to design the optimum joist girder for the loading conditions and the span. The different panel point configurations presented below can be specified by the building designer for architectural purposes or large duct openings. Type G: The panel points where the joists are bearing correspond to the intersection of the two diagonals at the top chord. Type VG: The panel points where the joists are bearing correspond to the position of the secondary web members (verticals) on the top chord. PrattWarrenModified Warren Combined geometries Type G configuration Type VG configuration 26 Standard details
  26. 26. Type BG: The panel points where the joists are bearing correspond to the position of the secondary web members (verticals) and the intersection of the two diagonals at the top chord. The shape of a joist may depend on its use and the type of roofing system requested by the customer. It can take one or more of the following shapes: STANDARD SHAPE NON-STANDARD SHAPES ** SPECIAL SHAPES ** Depending on the radius of curvature, the angles composing the top and/or bottom chord could require a rolling operation. * The building designer must consider in the design that the shapes can produce significant horizontal forces and/or movement on the supporting structure due to the deflection of the joist. ** Non-standard shapes and special shapes are more expensive due to their complexity. Type BG configuration 1 slope 1 slope 2 slopes Variable 4 slopes Variable (typ.) 2 slopes Variable 3 slopes Variable (typ.) 4 slopes Variable (typ.) 3 slopes Variable (typ.) 3 slopes Variable (typ.) Parallel chords Scissor * Bowstring R Barrel *R1 R 2 Scissor 27 Standard details
  27. 27. Minimum depth and span For fabrication reasons, the building designer must consider that minimum joist depth is limited to 200 mm (8 in.) and minimum joist span is limited to 2 450 mm (8 ft.). For shorter spans, joist substitutes, usually made of 1 or 2 channels, can be specified by the building designer or proposed by Canam. Shoes The standard shoe dimensions vary according to product and span: Product Span Depth Min. length Joist 2,450 mm (8 ft.) – 15,200 mm (50 ft.) 100 mm (4 in.) 100 mm (4 in.) 15,200 mm (50 ft.) – 27,400 mm (90 ft.) 125 mm (5 in.) 100 mm (4 in.) 27,400 mm (90 ft.) and over 190 mm (7 1/2 in.) 150 mm (6 in.) Joist girder All lengths 190 mm (7 1/2 in.) 150 mm (6 in.) However specific customer requests can be accommodated. The shoe depth must always be specified at the gridline. For joists on which the left and right bearings are not at the same level (sloped joist), the exterior and interior shoe depths are determined in such a way as to respect the depth at the gridline. To ensure that the intersection point of the end diagonal and the top chord occurs above the bearing, the minimum shoe depth should be specified according to the slope of the joist and the clearance of the supporting member from the gridline. Shoedepthatgridline Exteriorshoedepth Interiorshoedepth Shoedepthatgridline Exteriorshoedepth Interiorshoedepth Depthatgridline x Clearance 250 (metric) 12 (imperial) 28 Standard details
  28. 28. Metric imperial Clearance of bearing (mm) Sloped joist (x/250) 25 50 75 100 125 150 175 200 65 100 100 100 100 100 125 150 175 75 100 100 100 100 125 150 175 200 100 100 100 125 125 150 175 225 250 125 100 125 150 175 200 225 275 325 150 125 150 175 200 225 275 325 400 Clearance of bearing (in.) Sloped joist (x/12) 1 2 3 4 5 6 7 8 2 1/2 4 4 4 4 4 4 5 5 3 4 4 4 4 4 5 6 6 4 4 4 4 5 6 6 7 8 5 4 4 5 6 7 8 9 10 6 4 5 6 7 8 9 11 12 Minimum shoe depth (mm) Minimum shoe depth (in.) PARTICULARITIES BEARING ON CONCRETE OR MASONRY WALL The building designer shall allow for a bearing plate for the joist girder. The plate shall be in accordance with CAN/CSA S304.1-04 Standard if used for a masonry wall and CAN/CSA A23.3-04 Standard if used on concrete. The plate shall have minimum dimensions in length and width to ensure a minimum bearing for the joist girder of 150 mm (6 in.) and to allow the horizontal legs of the seat to be welded to the bearing plate. BEARING ON STEEL The joist girder shall be extended on the steel support to respect the minimum bearing of 100 mm (4 in.). The building designer must ensure that the type of connection and bearing support used respect this criteria. 29 Standard details
  29. 29. Details Ceiling extension Flush shoe A flush shoe can be used when the joist reaction does not exceed 45 kN (10 kip). Bolted splice In certain cases, joists are delivered in two sections. This is usually done because of transportation considerations, difficult installation conditions in an existing building,ordippingtankdimensionlimitationswhenajoistreceiveshotgalvanization treatment. A bolted splice is usually made at mid span. The number and position of plates and bolts can vary according to the loads to be transferred. We use high-strength bolts that meet ASTM A325 or ASTM A490 standards. A A Section A A A B B Section A Section B Bolted splice at top chord Bolted splice at bottom chord 30 Standard details
  30. 30. Depending on dimensions and quantities, joists can be fabricated as a single piece that is split into two sections for shipping, or fabricated as two separate pieces. In the plant, two additional metal tags are attached to the central part of the joist to ensure correspondence of male and female parts. Joists fabricated as a single piece will have two identical metal tags in the central part of the joist. On the other hand, joists fabricated as two separate pieces will have different metal tags. Example of identification for a joist fabricated as a single piece: If multiple joists with the same mark are fabricated, placement of the male section of the first joist must correspond with placement of the female section of the first joist, and so forth in the same manner. Examples: T1-1 with T1-1, T1-2 with T1-2, etc. Example of identification for a joist fabricated as two separate pieces: If multiple joists with the same mark are fabricated, the male sections can be arranged with any female section of the joist. They will be identified in the following manner: T1-L with T1-R. BOTTOM CHORD BEARING When the joist bearing is on the bottom chord, the top chord must be laterally supported with bridging. CANTILEVER JOIST A cantilever joist can have bearing on the top or bottom chord. The bottom chord must be adequately braced to resist compression loads caused by the cantilever. It is good practice to install a bridging row next to the joist support as well as at the end of its cantilevers. Top chord bearing requires bolted splices on the bottom chord. Bottom chord bearing Top chord bearing Erection drawing mark tag T1 Male and female section tags T1-1 T1-1 Erection drawing mark tag T1 Male and female section tags T1-L T1-R 31 Standard details
  31. 31. Joist and joist girder identification Joists and joist girders are identified on erection drawings by piece marks, examples: T1, T1A, J1, M2, etc. Joists and joist girders from the same family (T1, T1A) usually have the same chords but differ in terms of connections. Identical joists and joist girders have the same piece mark. Piece marks are indicated on the drawing near one of the ends of the line representing the joist or joist girder. At the plant, a metal identification tag is attached to the left end of the joist or joist girder. It is essential that the joist or joist girder be erected so that the metal tag is positioned at the same end of the building as indicated on the erection drawing. Standard connections Use of Canam standard connection details is strongly recommended for the following reasons: • Standardization of fabrication information; • Faster drawing checking; • Minimized risk of error. However specific customer requests can be accommodated. The standard connection details can be downloaded from the Canam web site at:  www.canam-construction.com. Below is the list of available connection details: • Joists – bearing on steel structures; • Joists – bearing on concrete structures; • Joist girders – bearing on steel structures; • Joist girders – bearing on concrete structures. Hillcrest Curling Facility  I  Vancouver, British Columbia Nemaska First Nation Sports Complex I Nemiscau, Quebec 32 Standard details
  32. 32. Surface preparation plays a significant role in paint performance. Adequate surface preparation allows the paint to adhere to structural steel, providing improved protection against corrosion. The level of preparation and the paint application method both depend on the type of environment to which the steel will be exposed. Thanks to ultramodern equipment selected to meet the most demanding requirements, Canam Group is poised to offer surface preparation, metallizing and painting services for all types and scales of structural steel and metal components. Treatment processes are based on the latest technologies in order to achieve optimum results. Paint standards In 1975, The Canadian Institute of Steel Construction (CISC) in cooperation with the Canadian Paint Manufacturers’ Association (CPMA) published reference documents related to the paint specifications for structural steel. The CISC/CPMA 1-73a paint standard applies to a quickdrying one-coat paint for use on structural steel that provides adequate protection against exposure to a non-corrosive environment as found in rural, urban, or semi-industrial settings, for a period not exceeding six months. Painted structural steel building components using this standard should not be used on permanent exterior exposed applications. Exposure of this product in coastal or high industrial areas may cause advanced deterioration of paint applied to this specification. Surface preparation may be limited to Solvent Cleaning (SSPC SP1) or Hand Tool Cleaning (SSPC SP2). Because of possible noncompatibility of this paint with finish coats, this shop applied paint is not recommended for use as a primer for the application of a multi-layer paint system. The CISC/CPMA 2-75 paint standard applies to a quick-drying primer for use on structural steel. This one-coat primer provides acceptable protection when exposed to a mainly non-corrosive environment as found in a rural, urban, or semi-industrial settings, for a period not exceeding twelve months. Painted structural steel building components using this standard should not be used on permanent exterior exposed applications. Exposure of this product in coastal or high industrial areas may cause advanced deterioration of paint applied to this specification. Final surface preparation must be done by Brush-Off Blast Cleaning (SSPC SP7). This layer of primer is usually covered with a finish coat according to the paint supplier’s recommendations. Dip coating is commonly used to apply paint for one or more of the above standards. When compared with spraying, experts in the field recommend application by dipping because it provides improved coverage of exposed surfaces. Although a coat of paint applied by dipping does not create an even dry film layer, it does not reduce its protection against corrosion. Paint costs Canam uses a single type of paint that meets both the CISC/CPMA 1-73a and CISC/ CPMA 2-75 specifications. The cost difference is mainly the result of two factors: surface preparation (SSPC SP2 or SSPC SP7) and the method of primer application (dipping or spraying). The following table compares paint costs according to final surface preparation and paint application methods for both paint standards. For example, for CISC/CPMA 1-73a type paint using SSPC SP2 final surface preparation, it is noted that spray painting is twelve times more expensive than dipping. 33 Surface preparation and paint
  33. 33. Selection Table for Paint Costs Paint type Surface  preparation Paint application cost factor Dipping Spraying CISC/CPMA 1-73a SSPC SP2 1 12 CISC/CPMA 2-75 SSPC SP7 6 16 Canam may apply paint that meets standards other than those specified in this document. Prices and delivery schedules are adjusted accordingly. For example, certain types of paint require nearly 24 hours before handling the joists. Colours Standard paint colour is gray. Red paint is optional. Joists exposed to the elements or corrosive conditions A high performance anti-corrosive paint is recommended for specification on joists permanently exposed to the elements or corrosive conditions during their service life. The building designer must pay special attention to item 6.5.7 of the CAN/CSA 16-01 standard. If a minimum thickness of material is required, it must be indicated on the drawings and specifications. When specified, joists may be hot dipped galvanized. Brush off blast cleaning surface preparation (SSPC SP7) is recommended to prevent scaling problems. In the galvanization process, the joists are acid washed, rinsed, and then dipped in a zinc bath at a temperature of 450°C (840°F). The depth and span of joists are limited by the size of the subcontractor’s galvanizing tanks. (Reference: www.galvanizeit.org) For strict conditions of hygiene, such as for meat products or food processing, it is recommended that the building designer specifies sealed welds. If the welds are not sealed, there is a risk that the acid used in the cleaning process remains trapped between the surface of the steel and causes acid bleeding through ruptures in the zinc film caused by pressure. The building designer must limit specification of sealed joints unless absolutely necessary because sealed joints require additional shop time. For galvanization, the thickness of the top and bottom chords shall be at least 4 mm (0.157 in.), and 3 mm (0.118 in.) for the web members, to avoid permanent deformation of the chords from overheating. Galvanized joists may also be painted. The building designer must ensure compatibility between the paint type and the galvanization product. 34 Surface preparation and paint
  34. 34. Steel joist floor vibration comparison The increased use of longer spans and lighter floor systems has resulted in the need to address the problem of floor vibration. The building structural designer must analyze floor vibration and its effect on the building end users and specify the proper characteristics to reduce vibration. The behavior of two-way flooring systems has been studied using models and in-situ testing. Several simplified equations have been developed to predict floor behavior and damping values for walking induced vibration and have been established according to the type of wall partitions and floor finishes. These equations are now part of Appendix E, a non-mandatory part of CSA standard S16 since 1984. In 2005, the National Building Code also addressed this issue at the Appendix D of the user guide. Steel Design Guide no. 11 – Floor vibrations due to human activity, jointly published by the American and Canadian institutes of steel construction in 1997, contains more recent information on the subject. This guide covers different types of floor vibrations and is one of the main references of Appendix E of standard CAN/CSA S16-01. The formulas shown in these publications allow the user to define the vibration characteristics of a floor system: the initial acceleration produced by a heel drop and the natural frequency of the system. These two parameters allow the designer to verify if the floor system will produce vertical oscillations in resonance with rhythmic human activities or with enough amplitude to disturb other occupants. The amplitude of the vibrations will decay according to the type of partitions, ceiling suspensions, and floor finish. The decay rate will also influence the sensitivity of the occupants. This information is not readily available to the joist supplier. The joist supplier usually receives only the floor drawings and general joist specifications and this information is used for joist design. Furthermore, the following examples show that the design of a joist, for which spacing, depth, span, bearing support, and dead loads have all been predetermined by the project structural engineer, cannot be easily modified to reduce floor vibration induced by walking below the annoyance threshold for the other occupants. The example is given for office floors where the annoyance threshold is defined as a floor acceleration of 0.5% of the gravity acceleration. For floors in a shopping centre, the threshold would be an acceleration of 1.5% of the gravity acceleration. This higher threshold means that the occupants are less disturbed by vibrations produced by walking loads. 35 Vibration
  35. 35. TYPICAL OFFICE FLOOR USED AS BASE In the example, the joists have a 9,000 mm (29 ft.-6 ¼ in.) span, a 500 mm (approx. 20 in.) depth, and are spaced at 1,200 mm (3 ft.-11 ¼ in.) on center. The joists are bearing on beams at both ends on 100 mm deep seats. We consider that the beams will only be partially composite for vibration calculations because of the relative lack of lateral stiffness of such a bearing seat. The beam span is 7,500 mm (24 ft.-7 ¼ in.) with joists on one side only. The floor is composed of a 100 mm (4 in.) concrete slab, including the 38 mm (1 ½ in.) steel deck profile. The loads are as follows: Structural steel 0.25 kPa ( 5 psf) Steel joists 0.20 kPa ( 4 psf) Deck-slab of 100 mm 1.87 kPa (39 psf) Ceiling, mechanical floor finish 0.50 kPa (10 psf) Partitions 1.00 kPa (21 psf) DEAD LOAD TOTAL 3.82 kPa (79 psf) LIVE LOAD 2.40 kPa (50 psf) From the Canam catalog, select a joist with a 9-meter (29 ft.-6 3 ⁄8 in.)span to support the following load: wf = 1.2 m x (3.82 x 1.25 + 2.4 x 1.5) = 10.05 kN/m The 9-meter (29 ft.-½ in.) selection table indicates that joists with a 10.5 kN/m factored capacity will weigh 16.7 kg/m and that 66% of the service load will produce a deflection value of span/360. By reducing the simple span deflection formula under uniform load for span/360, we obtain the following approximation of the moment of inertia: Ijoist = 23,436 x percentage x ws x (span)3 where Ijoist = moment of inertia in mm4 percentage = value shown in table for deflection / 100 ws = total service load (total factored load / 1.5) span = span of joist in meters Ijoist = 23,436 x (66 / 100) x (10.5 / 1.5) x (9)3 = 79 x 106 mm4 The center of gravity of the joist can be assumed to be at mid depth: Ajoist chords = Ijoist / (depth / 2)2 = 1,263 mm2 A beam can be chosen from the selection tables published by the CISC (assuming that the beam supports joists on both sides): W530 x 74 (W21 x 50) with Fy = 350 MPa (50 ksi) and a moment of inertia of 156 x 106  mm4 Notes: This example is based on International System of Units (SI) measurements. An approximate conversion of certain values is provided in parentheses for reference purposes. Take care not to confuse composite moment of inertia and modified moment of inertia (equation 3.15) with effective moment of inertia (equation 3.18) in Guide No. 11. The moment of inertia specified on the drawings must be the joist moment of inertia based on the top and bottom chords. Always specify the type of moment of inertia that is indicated on the drawings. 36 Vibration
  36. 36. Alternative 1 If a slab of 140 mm (5 in.) instead of 100 mm (4 in.) is used, the dead load increases and the size of the joists and beams will also increase. Structural steel 0.25 kPa ( 5 psf) Steel joists 0.20 kPa ( 4 psf) Deck-slab of 140 mm 2.79 kPa (58 psf) Ceiling, mechanical floor finish 0.50 kPa (10 psf) Partitions 1.00 kPa (21 psf) DEAD LOAD TOTAL 4.74 kPa (98 psf) LIVE LOAD 2.40 kPa (50 psf) From the Canam catalog, select a joist with a 9-meter (29 ft.-6 3 ⁄8 in.) span to support the following load: wf = 1.2 m x (4.74 x 1.25 + 2.4 x 1.5) = 11.43 kN/m The table indicates that the joists will weigh 18.2 kg/m and that 64% of the service load will produce a deflection value of span/360. Ijoist = 23,436 x (64 / 100) x (12 / 1.5) x (9)3 = 88 x 106 mm4 The center of gravity of the joist can be assumed to be at mid depth: Ajoist chords = Ijoist / (depth / 2)2 = 1,400 mm2 This time, the beam chosen from the CISC selection tables (considering that the beam support each side of the joists): W530 x 82 (W21 x 55) with Fy = 350 MPa (50 ksi) and Ix = 478 x 106 mm4 Note: This example is based on International System of Units (SI) measurements. An approximate conversion of certain values is provided in parentheses for reference purposes. Alternative 2 Starting from the base example, we consider that the structural engineer of the building clearly indicates that the size of the joists should be doubled to reduce floor vibration. Using the data of those 3 conditions, with the proposed equations of Steel Design Guide no. 11 published jointly by the American and Canadian institutes for steel construction, we obtain the vibration properties shown in the following comparison table: 37 Vibration
  37. 37. This comparison shows that the vibration characteristics improve by adding dead weight rather than by doubling the joist non-composite moment of inertia. One must note that the alternative 2 used did not sufficiently improve the vibration properties of the floor to lower their amplitude to below the annoyance threshold for offices. Additional calculations indicate that using a 125 mm (5 in.) deck-slab with a 100% increase in the joist and beam sections would lower the vibration amplitude to below the annoyance threshold of 0.5% of g. The building designer controls the main parameters affecting floor vibration characteristics and he or she should make the vibration calculations to find an economical solution. The information supplied in this catalog will allow the structural engineer to evaluate the vibration properties of the floor during the initial design. The structural engineer of the project should always specify the proper slab thickness and the minimum moment of inertia of the steel joists to have a floor with vibration characteristics below the annoyance threshold based on the type of occupancy. The joist designer will ensure conformity to the minimum moment of inertia required by the building designer for the joists (see clause 16.5.15 vibration). Please note that the analysis of floors subject to rhythmic vibrations (dance floor) is different from that performed for vibrations caused by walking (Steel Design Guide, no. 11 – Floor vibrations due to human activity, chapter 5). Finally, here are a few tips to obtain satisfactory vibration behavior: • increase the thickness of the concrete slab; • increase beam moment of inertia; • give special consideration to perimeter beams and joists; • add shear transfer elements or shear studs between the beam and the concrete slab to obtain a composite action; • reduce the span of joists and beams; • increase joist moment of inertia. COMPARISON OF VARIOUS ARRANGEMENTS Parameter Base Alternative 1 (increased thickness of slab by 30 mm) Alternative 2 (increased joist moment of inertia) Peak acceleration ao (% g) 0.80 % 0.50 % 0.57 % System frequency f (Hz) 4.5 4.5 5 Joist length (mm) 9,000 9,000 9,000 Joist depth (mm) 500 500 500 Joist spacing (mm) 1,200 1,200 1,200 Composite joist moment of inertia (106 mm4 ) 198 256 372 Deck depth (mm) 38 38 38 Slab-deck thickness (mm) 100 140 100 Slab-deck-joist dead weight (kPa) 1.87 2.79 1.87 Additional participating load (kPa) 1.00 1.00 1.00 Beam size W530 x 74 W530 x 82 W530 x 74 Beam span (mm) 7,500 7,500 7,500 38 Vibration
  38. 38. Special joist deflection Appendix D of the CAN/CSA S16-01 standard provides recommended maximum values for deflections for specified design live and wind loads. The following are the maximum values of appendix D recommended for the vertical deflection: Building type Specified loading Application Maximum Industrial Live Members supporting inelastic roof coverings. L/240 Live Members supporting inelastic roof coverings. L/180 Live Members supporting floors. L/300 Maximum wheel loads (no impact) Crane runway girders for crane capacity of 225 kN and over. L/800 Maximum wheel loads (no impact) Crane runway girders for crane capacity of 225 kN. L/600 All others Live Members of floors and roofs supporting construction and finishes susceptible to cracking. L/360 Live Members of floors and roofs supporting construction and finishes not susceptible to cracking. L/300 Notes: As mentioned in Appendix D, the designer should consider the inclusion of specified dead loads in some instances. For example, nonpermanent partitions, which are classified by the National Building Code as dead load, should be part of the loading considered under Appendix D if they are likely to be applied to the structure after the completion of finishes susceptible to cracking. Please note that the concrete cover at the centre line of the joist will be reduced by the amount of camber provided minus the deflection realized under self weight of the concrete alone. This must be accounted by the designer of the building with respect to the serviceability and fire resistance, etc. DEFLECTION OF CANTILEVERED JOISTS It is important to note that in the calculation of the allowable deflection of cantilevered joists, we consider that the cantilever end length L is equivalent to twice its length, as mentioned in Commentary D of the National Building Code of Canada (NBC) 2005 User's Guide. Therefore, for a 1,000 mm (3 ft.-3 in.) cantilever end length with a deflection criteria of L/240, the maximum allowable deflection is 2 x 1,000/240 = 8 mm (5 ⁄16 in.). CAMBER Camber is specified by the building designer on the plans and specifications. Unless otherwise indicated by the designer, the standards are applied as stated in Clause 6.2.2.1 of the CAN/CSA S16-01 Standard and the joist girders are cambered to compensate for the deflection due to the dead load. Joist girders with a span of 25 m (82 ft.) or more are cambered for the dead load plus one half of the service load. In some cases, camber must be restricted for joists and joist girders adjacent to non-flexible walls. 1,000 mm (3 ft.-3 in.) 39 Special conditions
  39. 39. Special loads and moments Canadian standards classify loads in the following manner: permanent, service, seismic, and wind loads. For limit states design, loads are factored and combined to obtain the worst possible effect. Loads applied to joists and joist girders can be uniform, partial, concentrated, axial, or moment. Snow pile up loads represent a special partial load case. Uplift loads are applied in an upward direction and should always be specified as a gross uplift load. Loads can be applied to the top chord, the bottom chord, or to both chords. When specifying the dead load, the building designer should always include the self-weight of the joists and bridging. Unless clearly specified, Canam will assume that the self-weight of joists is included in the total dead load. TRANSFER OF AXIAL LOADS Wind and seismic loads are usually transferred by the roof diaphragm to the axes of the vertical bracing system. The seismic loads transferred have a cumulative effect along these axes. The building design engineer specifies these loads on the plans and specifications. The transfer of an axial load between joists along the axes of the vertical bracing system, may require the reinforcement of the first panel at top. Transfer of axial loads Joist(axial) A Lateral load Section A-A Axial: an additional load specified by the building designer must be considered. Joist(axial) Joist(axial) Joist(axial) A Uniform Triangular At any panel point AnywhereAt a specific location VARIOUS TYPES OF LOADS Moment load Axial load Concentrated load Snow pile up load Partial load Uniform load 40 Special conditions
  40. 40. 41 Special conditions The building designer may consider a lateral factored capacity of 4.5 kN (1,000 lb) for the joist seats for the transfer of the deck shear forces to the girder top chord. Adding shear connectors between the joists on the girder increases the capacity to transfer diaphragm shear forces. Depending on the specifications of the building designer, axial loads between two joist girders may be transferred to the top chord as follows: • By angles placed under the top chord of the joist girders (suggestion 1); • By a transfer plate placed on the top of the top chord (suggestion 2); • By a transfer plate placed between the two angles of the top chord of the joist girders (suggestion 3); • Without a transfer piece using the capacity of the joist girder shoes (suggestion 4). Although not illustrated, the transfer of an axial load by the base of the shoe, usually requires bracing of the first panel of the top chord. In the case where a joist girder has adjacent bracing, the effect is represented by an axial load applied to the bottom chord. Transfer on an axial load by two angles placed under the top chord Suggestion 1 Section A-A A A Supplied by the steel contractor unless otherwise noted. Transfer of an axial load by a plate placed on the top of the top chord Suggestion 2 Supplied by the steel contractor unless otherwise noted. Transfer of an axial load by a plate placed between the angles of the top chord Suggestion 3 A A Section A-A Supplied by the steel contractor unless otherwise noted. Transfer of an axial load using the shoes Suggestion 4 Transfer of an axial load at the bottom chord and
  41. 41. 42 Special conditions UNBALANCED LOADS As with a steel supporting beam, the joist girder can have an unbalanced load on its longitudinal axis. Joists distributed on either side of the joist girder may be at different lengths or the loads they support may vary. This situation causes torsional stress in the joist girder, which will be considered by the joist girder designer. Therefore the designer could specify larger chords and web members for the joist girder and add additional knee braces between the bottom chord of the joist girders and the joists bearing on them. However, to avoid unbalanced loads, the joists must be staggered on each side of the joist girder: The offsetting of joists bearing on the joist girder will be considered by Canam during the design stage. LOAD REDUCTION ACCORDING TO TRIBUTARY AREA Although a joist girder may have a tributary area that is much larger than that of a joist, a reduction of the live load allowed by the National Building Code of Canada in Clause 4.1.6.9 is very limited. In fact, no reduction is permitted for a live load due to snow or an assembly area designed for a live load less than 4.8 kPa (100 psf). The reduction is applicable for a specific use and a minimal surface area (reference: NBC 2005, Clauses 4.1.6.9.2 and 4.1.6.9.3). Unbalanced loading R1 R2 Joist girder Joist girder R1 R2 Joist girder Staggered joists New spacings for staggered joists 2.2 m 7’ - 2” 2 m 6’ - 8” 2 m 6’ - 8” 2 m 6’ - 8” 2 m 6’ - 8” 1.9 m 6’ - 2” 2 m 6’ - 8” 2 m 6’ - 8” 2 m 6’ - 8” 2 m 6’ - 8” 2 m 6’ - 8” 2 m 6’ - 8” Joist girder Joist Joist Centre of reaction CL Joists are staggered as required Joist girder Joist girder Joist girder top chord
  42. 42. Gravitational moments End moments GRAVITATIONAL MOMENTS The use of a joist or joist girder in a rigid frame relieves the top chord and carries the compression loads to the bottom chord. End moments, as specified by the building designer on the plans and specifications, result in the analysis of a frame with defined moments of inertia. It is recommended that the building designer specifies minimum and maximum limits of inertia to ensure that the frame is designed according to the analysis model. The moment of inertia of the joist girder may be estimated using the equation below in either metric or imperial. MeTRIc I = 1,596 MfD where I = Moment of inertia of the joist girder (mm4 ) Mf = Factored bending moment (kN•m) D = Depth of joist girder (mm) Note : Mf may be calculated by considering a uniform load applied to the joist girder. Mf = (1.25DL + 1.5LL) x l x L2 8 where DL = Dead load (kPa) LL = Live load (kPa) l = Tributary width of joist girder (m) L = Joist girder span (m) IMPeRIAL I = 0.132 MfD where I = Moment of inertia of the joist girder (in.4 ) Mf = Factored bending moment (kip•ft.) D = Depth of joist girder (in.) Note : Mf may be calculated using a uniform loading applied to the joist girder. Mf = (1.25DL + 1.5LL) x l x L2 8,000 where DL = Dead load (psf) LL = Live load (psf) l = Tributary width of joist girder (ft.) L = Joist girder span (ft.) 43 Special conditions
  43. 43. WIND MOMENTS Horizontal wind loads on a joist or joist girder in a rigid frame may cause alternating moments as shown beside. Consequently, the joist will be analyzed with opposite moments. Examples: Case No. 1 - 10 kN•m and + 10 kN•m Case No. 2 + 10 kN•m and - 10 kN•m Joist or joist girder analysis and design The erection plans, supplied by Canam, usually instruct the erector to fasten the bottom chord after all of the dead loads have been applied. In this way, the joist or joist girder follows the condition for simple span condition under dead loads. In the case of end gravity moments, Canam will assume that they are caused only by the live load, unless otherwise specified by the building designer. When end moments are specified, the joist or joist girder shall first be designed to support loads on simple span condition. Then according to the combination of defined loads in the codes, different loading scenarios can be generated during analysis of the joist or joist girder. Each element shall be designed for worst-case conditions, whether simple span or with end moments. In addition to providing the end moment values applicable to the joist or joist girder, the building designer must pay special attention to ensure that the end connections develop the moments for which the building was designed. As in the case of the transfer of axial loads, the transfer of loads generated by an end moment may require the reinforcement of the first panel at top chord or by another type of reinforcement calculated according to the load. The end moment transferred to the joist girder can divide into forces in opposite directions (couple) applied to the top and bottom chords. For a connection with a transfer plate, the couple is calculated as follows: Tf = Cf = Mf de where Tf = Cf = Axial force (kN or kip) Mf = Factored moment connection ((kN•m or kip•pi) de = Effective joist girder depth (m or ft.) Wind moments Connection at bottom chord with a tie joist plate Transfer of the loads via a transfer plate Transfer plate supplied by the steel contractor unless otherwise noted. Stabilizer plate supplied by the steel contractor unless otherwise noted. Mf Tf or Cf de Tf or Cf 44 Special conditions
  44. 44. For a connection where the loads are carried by the shoe base, the axial force increases due to a shorter moment arm. Tf = Cf = Mf de where Tf = Cf = Axial force (kN or kip) Mf = Factored moment connection ((kN•m or kip•pi) de = Effective joist girder depth (m or ft.) Since the loads transferred by the base of the shoe create significant eccentricity, normally the first panel must be reinforced by the joist girder engineer. Different types of reinforcement of the first panel are presented below. Some connections to the bottom chord of joist or joist girder use an angle welded to the column and a tie joist plate shop welded to the joist girder. However, this type of connection, as shown beside, is no longer recommended. A standard connection with a stabilizer plate is more simple and gives the same lateral stability. The steel contractor usually supplies the steel plate on the column at the location of the bottom chord of the joist girder. The plate is inserted between the vertical flanges of the bottom chord angles. A plate should have a thickness of 13 mm (½ in.) or 19 mm (¾ in.). A hole in the stabilizer plate allows the column to be plumbed with guy wires. The transfer of forces from the column to the bottom chord is achieved by welding the angles of the bottom chord to the plate, as indicated beside. Vertical eccentricity at bearing due to the axial load e Transfer of the loads by the shoe base Tf or Cf de Tf or Cf Mf Joist girder shoe Stabilizer plate supplied by the steel contractor unless otherwise noted. Mf Different types of reinforcement of the first panel e A- Addition of a strut e B- Addition of stiffener plate e C- Shoe extension Standard connection at bottom chord with a stabilizer plate Only in the case or we must transfer from the efforts. Section A-A A A 45 Special conditions

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