TABLE OF CONTENTS. steel

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2 TABLE OF CONTENTS PAGE SUBJECT steel Corporation Pages identified with a red tab or the Canam logo as shown above are Canam s supplement to the Steel Joist Institute (SJI) 41 st EDITION, STANDARD SPECIFICATIONS, LOAD TABLES & WEIGHT TABLES FOR STEEL JOISTS AND JOIST GIRDERS, meant to advance the easy application of steel joists in North American construction. 6 Quality Assurance 8 Detailing with Open Web Steel Joists Combined Bridging Tables Girder and Joist Connections, Bridging Details Square Ends, Added Members, Uplift Sloped Seats Field Bolted Splice, Pitched Joists, Duct Openings 16 Engineering with Open Web Steel Joists Load / Span Design, Sloped Joists, Special Loads End Moments Standing Seam Roof, Joists Longer than SJI Special Shapes OSHA Highlights Floor Vibration Joist Substitutes, Outriggers and Extensions, Headers Design Economy 30 Steel Joist Institute History and General Information 2002 Revisions to Specifications SJI History SJI Policy, Membership, Publications SJI Joists and Fire Resistance 37 SJI K-Series K-Series TCX, Extended Ends K-Series Specs Sections 1 through 6 K-Series Definition of span K-Series Standard Load Tables Pages identified with the black tab or the SJI logo as shown above are a reproduction of the SJI s 41 st EDITION, STANDARD SPECIFICATIONS, LOAD TABLES & WEIGHT TABLES FOR STEEL JOISTS AND JOIST GIRDERS, provided in this catalog by Canam. 54 SJI KCS and K-Series Economy Tables K-Series KCS joists example K-Series KCS joists Load Table K-Series Economy Table 62 SJI LH & DLH Series LH-DLH-Series Specs Sections 100 through 105 LH-Series Std Load Table DLH-Series Std Load Table 78 SJI Joist Girders Joist Girders Specs Sections 1000 to Canam Joist Girder Tables Conventional Girder, Wood Nailer Girder 96 Recommended Code of Standard Practice Sections 1 through 8 Referenced Specs, Codes, and Standards 105 Appendices on OSHA regulations Bay Length Definitions OSHA Steel Erection Std (OWSJ) Illustration of Bridging Terminus Canam and Design, Red Dot Design, Murox, and Sun Steel Buildings are registered trademarks of The Canam Manac Group Inc. Solutions + Services is a trademark of The Canam Manac Group Inc. Hambro is a trademark of Hambro International (Structures) Ltd. 114 Canam Lists Joist, Joist Girder, Bridging and Accessories Lists Take-off Sheets Mailing Addresses and Telephone Internet Addresses, Web Site Plan steel Corporation 3

3 steel Corporation 4

4 7 6 8 Gold Hill Vancouver Issaquah 4 Spokane Sunnyside Calgary 8 Wayzata Chicago 5 Overland Park Washington Indianapolis Détroit 2 Columbus Peru 9 Mississauga Québec 7 Saint-Gédéon Moncton Saint-Joseph Boucherville Laval Brockville Poland Spring Chittenango 6 Boston Madison Wynnewood 1 Baltimore Point of Rocks Purcellville Virginia Beach 9 Los Angeles Carlsbad Peoria Cordova Lawrenceville 11 Ciudad Juárez 3 Jacksonville San Antonio Chihuahua 10 Monterrey México 11 West Palm Beach Hypoluxo Deerfield Beach 10 Plant Canam Sales Office PLANTS UNITED STATES 1 Point of Rocks, Maryland 2 Columbus, Ohio 3 Jacksonville, Florida 4 Sunnyside, Washington 5 Washington, Missouri CANADA 6 Saint-Gédéon, Quebec 7 Boucherville, Quebec 8 Calgary, Alberta 9 Mississauga, Ontario MEXICO 10 Monterrey, Nuevo León 11 Ciudad Juárez, Chihuahua steel Corporation 5

5 GUIDING PRINCIPLES QUALITY ASSURANCE Total client satisfaction: exceptional service Excellent relations with our personnel First quality products: non-negotiable Low-cost producer Clean and orderly working environment Good corporate citizen steel Corporation 6

6 QUALITY ASSURANCE PLANT AND PRODUCT CERTIFICATIONS Over the years, we have established strict quality standards. All our welders, inspectors, and quality assurance technicians are certified by the American Welding Society or the Canadian Welding Bureau. We do visual inspections on 100% of the welded joints and non-destructive testing if required. Canada United States Mex. Plants Columbus, OH Sunnyside, WA Jacksonville, FL Point of Rocks, MD Washington, MO Boucherville, QC Saint-Gédéon, QC Mississauga, ON Calgary, AB Juarez, CHIH Monterrey, NL SJI Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes AISC Cbd, Cbr, P Cbd, P Cbd Cbd, Cbr, P, F CWB Yes Yes Yes Yes Yes ISO UL Steel Deck Hambro Steel Deck & Hambro Steel Deck Hambro Steel Deck Hambro ULC Steel Deck Hambro Steel Deck Steel Deck ICBO Steel Deck & Plant Hambro Plant FM Steel Deck Steel Deck Steel Deck Steel Deck Steel Deck Steel Deck SJI: Steel Joist Institute AISC: American Institute of Steel Construction CWB: Canadian Welding Bureau ISO: International Organization for Standardization UL: Underwriters Laboratories ULC: Underwriters Laboratories of Canada ICBO: International Conference of Building Officials FM: Factory Mutual Cbd: Complex Steel Building Structures Cbr: Major Steel Bridges P: Sophisticated Paint Endorsement F: Fracture Critical Endorsement Canam has been producing open web steel joists for the last 40 years and has developed expertise in engineering and fabrication to better serve our customers with quality products. With five plants in the United States, three in Canada, and two in Mexico, the Canam team can deliver all types of joists where and when you need them from any of our SJI certified plants. In our search for quality, Canam has introduced a series of small cold formed channels to provide individual web members for most steel joists spanning over thirty feet. These straight web members allow an easier weld with the chord members. PAINT Canam s standard shop paint is GRAY primer. Other primer colors may be available at some locations. The typical shop applied primer that is used to coat steel joists and joist girders is a dip-applied, air dried paint. The primer is intended to be an impermanent and provisional coating which will protect the steel for only a short period of exposure in ordinary atmospheric conditions. Since most steel joists and joist girders are primed using a standard dip coating, the coating may not be uniform and may include drips, runs, and sags. Compatibility of any coating, including fire protective coatings, applied over standard shop primer shall be the responsibility of the specifier and/or painting contractor. The primer coating may require field touch-up/repair. The joist manufacturer shall not be responsible for the condition of the primer if it is not properly protected after delivery. ENGINEERING & DRAFTING Our engineering staff is ready and willing to help you with any technical matters you may have with the use of open web steel joists. We have developed a taste for technically challenging projects. We like to innovate and find what s best for our customers. Canam has developed enough drafting capacity so that 100% of our drawings are done by Canam employees. Canam is not using sub-contractors to perform any of our technical work. This way, we can ensure quick response time, quality, and consistency to our customers. steel Corporation 7

7 DETAILING WITH OPEN WEB STEEL JOISTS COMBINED BRIDGING TABLES K-SERIES NUMBER OF ROWS OF BRIDGING** Refer to the K-Series Load Table and Specification Section 6 for required bolted diagonal bridging. Distances are Joist Span lengths See Definition of Span on page 49. *Section Number Row Rows Rows Rows Rows #1 Up thru 16 Over 16 thru 24 Over 24 thru 28 #2 Up thru 17 Over 17 thru 25 Over 25 thru 32 #3 Up thru 18 Over 18 thru 28 Over 28 thru 38 Over 38 thru 40 #4 Up thru 19 Over 19 thru 28 Over 28 thru 38 Over 38 thru 48 #5 Up thru 19 Over 19 thru 29 Over 29 thru 39 Over 39 thru 50 Over 50 thru 52 #6 Up thru 19 Over 19 thru 29 Over 29 thru 39 Over 39 thru 51 Over 51 thru 56 #7 Up thru 20 Over 20 thru 33 Over 33 thru 45 Over 45 thru 58 Over 58 thru 60 #8 Up thru 20 Over 20 thru 33 Over 33 thru 45 Over 45 thru 58 Over 58 thru 60 #9 Up thru 20 Over 20 thru 33 Over 33 thru 46 Over 46 thru 59 Over 59 thru 60 #10 Up thru 20 Over 20 thru 37 Over 37 thru 51 Over 51 thru 60 #11 Up thru 20 Over 20 thru 38 Over 38 thru 53 Over 53 thru 60 #12 Up thru 20 Over 20 thru 39 Over 39 thru 53 Over 53 thru 60 ** Last digit(s) of joist designation shown in Load Table. ** See Section 5.11 of the K-Series specification for additional bridging required for uplift design. MAXIMUM JOIST SPACING FOR HORIZONTAL BRIDGING **BRIDGING MATERIAL SIZE K-SERIES Round Rod Equal Leg Angles HR = Hot Rolled CF = Cold Formed 1-1/8 CF 1-3/8 CF 1-5/8 CF 1-7/8 CF 2-1/8 CF SECTION 1/2 round 1 HR 1-1/4 HR 1-1/2 HR 1-3/4 HR 2 HR 2-1/2 HR NUMBER* r =.13 r =.20 r =.25 r =.30 r =.35 r =.40 r =.50 1 thru and ** Refer to last digit(s) of Joist Designation ** Connection to Joist must resist 700 pounds Certain joists require bolted diagonal bridging for erection stability for spans less than 60 feet. The chart below lists those designations and the minimum spans at which bolted diagonal bridging is required. All joists over 60 feet require erection stability bridging. 12K1 23 ft. 22K4 34 ft. 26K10 49 ft. 24LH03 35 ft. 14K1 27 ft. 22K5 35 ft. 28K6 40 ft. 24LH04 39 ft. 16K2 29 ft. 22K6 36 ft. 28K7 43 ft. 24LH05 40 ft. 16K3 30 ft. 22K7 40 ft. 28K8 44 ft. 24LH06 45 ft. 16K4 32 ft. 22K9 40 ft. 28K9 45 ft. 28LH05 42 ft. 16K5 32 ft. 24K4 36 ft. 28K10 49 ft. 28LH06 46 ft. 18K3 31 ft. 24K5 38 ft. 28K12 53 ft. 28LH07 54 ft. 18K4 32 ft. 24K6 39 ft. 30K7 44 ft. 28LH08 54 ft. 18K5 33 ft. 24K7 43 ft. 30K8 45 ft. 32LH06 47 ft. 18K6 35 ft. 24K8 43 ft. 30K9 45 ft. 32LH07 47 ft. 20K3 32 ft. 24K9 44 ft. 30K10 50 ft. 32LH08 55 ft. 20K4 34 ft. 26K5 38 ft. 30K11 52 ft. 36LH07 47 ft. 20K5 34 ft. 26K6 39 ft. 30K12 54 ft. 36LH08 47 ft. 20K6 36 ft. 26K7 43 ft. 18LH02 33 ft. 36LH09 57 ft. 20K7 39 ft. 26K8 44 ft. 20LH02 33 ft. 20K9 39 ft. 26K9 44 ft. 20LH03 38 ft. On Canam s framing plans, the erection stability bridging lines are identified with the following symbol and notation: ES APPROVER / ERECTOR NOTE: Except for column joists noted as OC, All ERECTION STABILITY bridging lines shall be installed prior to the slackening of hoisting lines. steel Corporation 8

8 DETAILING WITH OPEN WEB STEEL JOISTS COMBINED BRIDGING TABLES For KCS-Series joists, use the tables for K-Series with an equivalent section number, as shown in the chart below: BRIDGING JOIST TABLE DESIGNATION SECT. NO. 10KCS1 1 10KCS2 1 10KCS3 1 12KCS1 3 12KCS2 5 12KCS3 5 14KCS1 4 14KCS2 6 14KCS3 6 16KCS2 6 16KCS3 9 16KCS4 9 16KCS5 9 18KCS2 6 18KCS3 9 18KCS KCS KCS2 6 20KCS3 9 20KCS KCS KCS2 6 22KCS3 9 22KCS KCS KCS2 6 24KCS3 9 24KCS KCS KCS2 6 26KCS3 9 26KCS KCS KCS2 6 28KCS3 9 28KCS KCS KCS3 9 30KCS KCS5 12 BRIDGING BOLT SIZES SECTION MINIMUM SERIES NUMBER BOLT SIZE K ALL 3/8 A307 LH/DLH /8 A307 LH/DLH /2 A307 or 3/8 A325 DLH 18 & 19 5/8 A307 or 1/2 A325 LH-DLH MAX. SPACING HORIZONTAL *SECTION OF LINES OF BRACING NUMBER BRIDGING FORCE lbs 02,03, , , , , , , , Number of lines of bridging is based on joist clear span dimensions. *Last two digits of joist designation shown in load table K, LH & DLH SERIES JOISTS MAXIMUM JOIST SPACING FOR DIAGONAL BRIDGING BRIDGING ANGLE SIZE - (Equal Leg Angles) HR = Hot Rolled CF = Cold Formed 1-1/8 CF 1-3/8 CF 1-5/8 CF 1-7/8 CF 2-1/8 CF JOIST 1 HR 1-1/4 HR 1-1/2 HR 1-3/4 HR 2 HR DEPTH r =.20 r =.25 r =.30 r =.35 r = LH SERIES JOISTS MAXIMUM JOIST SPACING FOR HORIZONTAL BRIDGING SPANS OVER 60 REQUIRE BOLTED DIAGONAL BRIDGING **BRIDGING ANGLE SIZE - (Equal Leg Angle) HR = Hot Rolled CF = Cold Formed 1-1/8 CF 1-3/8 CF 1-5/8 CF 1-7/8 CF 2-1/8 CF SECTION 1 HR 1-1/4 HR 1-1/2 HR 1-3/4 HR 2 HR 2-1/2 HR NUMBER* r =.20 r =.25 r =.30 r =.35 r =.40 r =.50 02, 03, ** Refer to last two digits of Joist Designation. ** Connection to joist must resist force listed in Table of the LH-Series specification. steel Corporation 9

9 DETAILING WITH OPEN WEB STEEL JOISTS GIRDER AND JOIST CONNECTIONS 3 3/4 ø BOLTS 5 GAGE 1-1/2 3/4 ø BOLTS 5 GAGE 2 3/4 ø BOLTS 5 GAGE 7-1/2 7-1/2 7-1/ /2 1 STABILIZER PLATE 1 STABILIZER PLATE 1 STABILIZER PLATE GIRDER CONNECTION BOLTS NOT BY CANAM A GIRDER CONNECTION BOLTS NOT BY CANAM B GIRDER CONNECTION BOLTS NOT BY CANAM C 3 3/4 ø BOLTS 5 GAGE 7-1/2 HALF STD GA 3/4 ø BOLTS 4 LH & DLH 1/2 ø BOLTS 3-1/2 K 2-1/2 3/4 ø BOLTS 4 LH & DLH 1/2 ø BOLTS 3-1/2 K K LH 6 K LH K LH 1 STABILIZER PLATE GIRDER CONNECTION BOLTS NOT BY CANAM D JOIST CONNECTION BOLTS NOT BY CANAM E 1 STABILIZER PLATE JOIST CONNECTION BOLTS NOT BY CANAM F 1-1/2 3/4 ø BOLTS 4 LH & DLH 1/2 ø BOLTS 3-1/2 K 2 3/4 ø BOLTS 4 LH & DLH 1/2 ø BOLTS 3-1/2 K 2-1/2 3/4 ø BOLTS 4 LH & DLH 1/2 ø BOLTS 3-1/2 K 3 K LH 1/2 K LH K LH 1 STABILIZER PLATE JOIST CONNECTION BOLTS NOT BY CANAM H 1 STABILIZER PLATE JOIST CONNECTION BOLTS NOT BY CANAM K DLH18 and DLH19 will have girder standards. K LH 1 JOIST CONNECTION BOLTS NOT BY CANAM STABILIZER PLATE L steel Corporation 10

10 DETAILING WITH OPEN WEB STEEL JOISTS GIRDER AND JOIST BEARING HORIZ. BRIDGING CUT TO FIT IN FIELD LAP TO BE 2 MIN USE ALL DROPS. See page 10 for standard girder and joist connections at columns. Joists not falling directly at a column line have to be welded and/or bolted depending on conditions. As per OSHA, any joists in bays over 40 and bearing on steel framing have to be bolted unless if the joists are assembled on the ground into panels and then set in place. Minimum welds are two 1/8 x 1 long fillet welds for K-Series and two 1/4 x 2 long fillet welds for LH and DLH-Series. K-Series joists shall bear at least 2 1/2 on steel and 4 on masonry while LH, DLH, and girder shall bear a minimum of 4 on steel and 6 on masonry. PLAN 2 2 1/8 1 TYP MIN BRIDGING DETAILS 1/8 1 TYP MIN SEE PLAN FOR PIECE MARK BRIDGING ANCHOR PIECE MARK BAC = 2 1/2 x 2 1/2 x 3/16 x 2 1/2 LONG ATTACH WITH: 1/2 EXP BOLT (NOT BY CANAM) BRIDGING ANCHOR PIECE MARK BAC = 2-1/2 x 2-1/2 x 3/16 x 2-1/2 LONG ATTACH WITH: 1/2 EXP BOLT (NOT BY CANAM) 1/4 2 LH SERIES 1/4 2 TYP. MIN. 1/8 1 K SERIES 1/8 1 TYP. MIN. WELDED-X BRIDGING SEE PLAN FOR PIECE MARK 1/8 2 MIN KNEE BRACE ONLY IF REQUIRED BY DESIGN SEE PLAN FOR LOCATIONS TYP MIN 1/8 1 steel Corporation 11

11 DETAILING WITH OPEN WEB STEEL JOISTS SQUARE ENDS ADDED MEMBERS Whenever joists are bottom chord bearing, a row of bolted diagonal cross bridging should be installed from joist to joist at or near the bearing location to provide lateral erection stability. OF PANEL POINT MORE THAN 3 3/16 as specified SQUARE END OF POINT LOAD The weight of walls, signage, facia, etc. supported at the end of a cantilever square end must be shown on the contract drawings to be properly considered in the joist design. FULL DEPTH CANTILEVER END OF PANEL POINT FIELD INSTALLED MORE THAN 3 ANGLE BRACE, EACH SIDE NOT BY CANAM~MINIMUM OF POINT LOAD LEG THICKNESS 3/16. TYPICAL JOIST REINFORCEMENT AT CONCENTRATED LOADS Joists, including KCS-Series, are not typically designed for localized bending from point loads. Concentrated loads must be applied at joist panel points or field strut angles must be utilized as shown. Canam can provide a specially designed joist with the capability to take point loads without the added struts, if this requirement and the exact location and magnitude of the loads are clearly shown on the contract drawings. Also, Canam can consider the worst case in both the shear and bending moment for a traveling load with no specific location. When a traveling load is specified, the contract drawings should indicate whether the load is to be applied at top or bottom chord, and at any panel point, or at any point with the local bending effects considered. UPLIFT Where uplift is a design consideration, the NET uplift value shall be provided on the contract drawings. Additional lines of bridging will be required at the first bottom chord panel points as shown. UPLIFT BRIDGING: 1 ROW OF HORIZONTAL FIRST BOTTOM CHORD PANEL POINT ON EACH END OF JOIST AS SHOWN. TYPICAL ALL JOISTS, ALL BAYS, IN ADDITION TO STANDARD BRIDGING SHOWN ON PLAN. FIRST BOTTOM CHORD PANEL POINT steel Corporation 12

12 DETAILING WITH OPEN WEB STEEL JOISTS SLOPED SEATS 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. Interior Shoe Depth Shoe Depth at gridline Exterior Shoe Depth Interior Shoe Depth Shoe Depth at gridline Exterior Shoe Depth Interior Shoe Depth Exterior Shoe Depth Shoe Depth at gridline Interior Shoe Depth Exterior Shoe Depth Shoe Depth at gridline The bearing depth should be increased at sloped joists to insure an adequate depth of bearing seat assembly at the inside end or at the outside end, which depends on which bearing end (left or right) is higher. x 12 Shoe Depth at gridline 2 1/2 MIN x /2 MIN Shoe Depth at gridline A A Reference lines (gridline) are always at center of bearing steel or inside face of wall. MINIMUM SHOE DEPTH AT GRIDLINE (in.) A Joist Sloped (x / 12) (in.) NOTE: Calculations are based on a top chord vertical leg of 2-1/2 (all K-Series and up to LH07). steel Corporation 13

13 DETAILING WITH OPEN WEB STEEL JOISTS FIELD BOLTED SPLICE Field bolted splices can be provided on any joist type when required for shipment or due to site constraints, such as a retrofit use. Note that spliced joists are normally fabricated as one complete piece in Canam s shops, and are then separated for shipment. In assembling the joist, the erector must match mates. The joist mates will be marked 1L and 1R or 2L and 2R and so on in addition to regular joist piece marks. Two dissimilar mates will not fit together properly. The metal tag for the left half of the spliced joists will be placed near the bearing end, and this end must be placed to match the tagged end on the framing plan. The metal tag for the right half is placed on the left end of this half, near the splice. PITCHED JOISTS Canam can provide longspan joists with a variety of pitched chord configurations. TOP CHORD SINGLE PITCHED UNDERSLUNG TOP CHORD SINGLE PITCHED SQUARE ENDS SPLICE TOP CHORD DOUBLE PITCHED UNDERSLUNG JOIST TOP CHORD SPLICE CONNECTION 1 TOP CHORD DOUBLE PITCHED SQUARE ENDS DUCT OPENINGS JOIST BOTTOM CHORD SPLICE CONNECTION NOTE: QUANTITY AND ARRANGEMENT OF BOLTS AND PLATES MAY VARY. ALL BOLTS ARE TO BE HIGH STRENGTH. (A325 OR A490) TYP. SPLICE DETAIL Open web steel joists allow the passage of pipes, conduits, and ducts through the joist. The specifier shall clearly show the size and exact location of ducts which have a fixed location and cannot be field located around the joist webs. To maximize the duct openings in a joist girder, the joist girder can be specified as a VG type. By aligning the vertical web members of the girder with the joists it supports, the duct opening in the girder, between the joists, is maximized. VG GIRDER DUCT steel Corporation 14

14 DETAILING WITH OPEN WEB STEEL JOISTS MAXIMUM DUCT OPENINGS DIMENSIONS OF FREE OPENINGS FOR VARIOUS JOIST AND JOIST GIRDER CONFIGURATIONS NOTE: Since dimension P could vary with the final design, final dimensions of free openings should be verified with Canam. P P P P H D L R S S H D L R S S WEB CONFIGURATIONS (in.) OPENINGS (in.) H P D S L R JOISTS When duct-opening dimensions exceed the limits above, some web members must be removed. The shear forces are then transferred through 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 8 (200 mm). 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 where more shear forces must be transferred through 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. WEB CONFIGURATIONS (in.) OPENINGS (in.) H P D S L R JOISTS WEB CONFIGURATIONS (in.) OPENINGS (in.) H P D S L R JOIST GIRDERS Location must be greater than 2.5 x H 4 min. H 4 min. steel Corporation 15

15 ENGINEERING WITH OPEN WEB STEEL JOISTS LOAD / SPAN DESIGN SPECIAL LOADS As an alternate to a standard joist designation in the load tables, Canam can design and manufacture a special load/span joist for the exact uniform load requirements. A load/span joist should be designated as follows: ddksptl/ll ie. 24KSP300/175 dd = depth in inches tl = total load in plf ll = live load in plf Live load deflection will be governed by L/360 for floors or L/240 for roof unless noted otherwise on the contract drawings. A load/span joist can be used for either K, LH or DLH-Series. DEAD LOAD= PT. LD. LIVE LOAD= PT. LD. PT. LD. SLOPED JOISTS For sloped joists, the load and span shall be defined as outlined below. This allows the use of the load tables for joists with slopes larger than 1/2 inch per foot. Span: The span of a parallel chord sloped joist shall be defined by the length along the slope. Minimum depth, loadcarrying capacity, and bridging requirements shall be determined by the sloped definition of span. The Standard Load Table capacity shall be the component normal to the joist. Load: Where the design live load is applied vertically over the plan length and the design dead load is applied vertically over the sloped length, select a joist with Load-Table capacity = LL*cos 2 α + DL*cos α Canam will automatically design for the component of the load parallel to the joist which acts as a top chord axial load. α SPAN α α LL DL α α LOAD-TABLE CAPACITY LL * cos 2 α DL * cos α Canam s design programs allow for the consideration of numerous special loading conditions. Where special loads, such as snow drifting or equipment loads, will be placed on a joist, the loading information can best be conveyed by using a load diagram such as the sample shown here. It is important for the load diagram to clearly indicate which point loads are applied at the joist top chord, and which are suspended from the bottom chord. And it is important to clearly locate mechanical loads to avoid delays in joist fabrication. Unless specifically instructed otherwise, it is assumed that field added strut angles will be utilized as described on page 12. Canam has two design capabilities which can be used to help accommodate variable loading conditions. First, a joist or girder can be designed with multiple loading cases. Each element of the joist or girder is then sized to handle the worst forces generated by any one of the loading conditions. For example, a joist may have a case one which has a uniform snow load and will create the controlling bending moment. Case two might have a snow drift together with a reduced uniform snow load, which may be a more severe condition for shear. A second capability is the ability to design for a traveling load. For each element of the joist or girder, the forces are determined for the most critical location of the load along the joist length. Traveling loads can be specified as being at any panel point along the top or bottom chord, or at ANY point along the top or bottom chord. By specifying a traveling load to be applied at ANY point, miscellaneous loads within the specified limit can be applied at any time during the life of the structure without the need for reinforcement or field added members. Canam s engineering staff can help find solutions for almost any special loading condition. steel Corporation 16

16 ENGINEERING WITH OPEN WEB STEEL JOISTS END MOMENTS Tie joists (joists at column lines) or joist girders can be successfully used as part of a moment frame in the structure. The frame analysis shall be performed by the specifier, and the resultant wind/seismic and continuity moments shall be shown on the contract drawings. For purposes of the frame analysis, the moment of inertia of a joist or joist girder can be approximated by the formulas on page 50, 73, 76, and 78, respectively, in this catalog. Detail A shows the suggested method of presenting the moment values, as well as the directions in which they will be applied. M M WL LL DETAIL A M M LL WL In addition to providing the end moment values on the contract drawings, the specifier must give due consideration to the connections in order to properly develop the end moments. At the joist or girder bottom chord, the connection can be made simply by welding the bottom chord directly to the column stabilizer plate (see Detail B). The typical gap provided between the bottom chord angles is one inch. As shown in Detail C, at the top chord considerable eccentricity will develop if the connection is made at the base of the bearing seat on a typical underslung end. A moment plate shall be used to allow direct transfer from the top chord to the column or abutting joist, similar to Details D and E. The specifier shall show the size of the plate and the required welds on the contract drawings. These moment plates are not included in Canam s bid, unless specified otherwise. Canam will presume that all continuity moments are induced by the live load, and unless otherwise instructed by the specifier, will presume that no dead load moment is present. It is Canam s standard practice to instruct the joist erector to complete the connection of the bottom chords to the columns only after all dead loads are applied. Thus, the joist will act only as a simply supported truss for the dead load case. Where end moments have been specified, Canam will first design the joist or joist girder as a simply supported member with the full gravity loads applied. This ensures adequate strength during construction before the end moment connection is completed, and also provides additional redundancy to the structure in the event that the moment connection is not successfully completed in the field. Canam will then apply all the appropriate combinations of the wind/seismic and continuity moments as a separate load case. Each chord and web member in the joist or joist girder will be designed for the worst condition of either the simple span or end moment case. e P M = P x e DETAIL C DETAIL D MOMENT PL TYP. (NOT BY CANAM) DETAIL B DETAIL E steel Corporation 17

17 ENGINEERING WITH OPEN WEB STEEL JOISTS STANDING SEAM ROOFS Where a standing seam roof is attached directly to the joist top chord, or any other instance where decking will not provide lateral support on the top chord, Canam will design a bridging system to provide the required top chord lateral support, in accordance with the following specifications of sections 5.8(g) or 104.9(g). STANDING SEAM ROOF SYSTEM JOIST TOP CHORD Ted Constant Center, Old Dominion University, Norfolk, VA JOISTS LONGER THAN SJI Canam has the capability to build joists, trusses, and joist girders with spans and depths beyond the limits of the Load Tables. The DLH-series Load Table extends to depths of 72 inches and spans of 144 feet. Canam can fabricate special joists with depths of over 10 feet and lengths over 200 feet. Special consideration is required for these very large joists, and attempting to select a standard joist from a load table may be an over-simplification of the true loading conditions and design requirements. Canam recommends that any joist that exceeds the range of the DLH-series Load Table be labeled as a special joist with a load diagram provided to allow accurate design of the joist. The load diagram should clearly indicate if the joist self weight is included in the design loads, or if the loads shown are only the superimposed loads to which self weight must be added. Due consideration must also be given to camber, deflection, bridging or bracing, and erection. Please consult Canam for assistance in specifying these joists. Canam has extensive experience in providing joists beyond the range of the Load Tables, including these recent projects: * Ford Field Stadium Detroit, MI 128 joists inches deep, 166 feet long, shipped in 2 pieces * Ted Constant Convocation Center Old Dominion University, Norfolk, VA 17 joists, 168 inches deep, 238 feet long, shipped in 3 pieces * Belmont University Nashville, TN 20 joists, 170 inches deep, 211 feet long, shipped in 3 pieces * York High School Elmhurst, IL 37 joists, 120 inches deep, 202 feet long, shipped in 2 pieces * Jordan Valley Park Expo Center Springfield, MO 35 pieces, 96 inches deep, 150 feet long, shipped in 2 pieces * Dubuque Riverfront Education Dubuque, IA 13 pieces, 168 inches deep bowstring, 150 feet long, shipped in 2 pieces * Idaho Sports Center Nampa, ID 11 pieces, 120 inches deep scissors, 175 feet long, shipped in 2 pieces * Palm Beach County Convention Center West Palm Beach, FL 179 pieces, 80 inches deep, 150 feet long, shipped in 2 pieces * Mohegan Sun Podium Uncasville, CT 43 pieces, 96 inches deep, 166 feet long, shipped in 3 pieces * Angelo State University s Junell Center San Angelo, TX 33 pieces, 120 inches deep, 224 feet long, shipped in 3 pieces steel Corporation 18

18 ENGINEERING WITH OPEN WEB STEEL JOISTS Junell Center, San Angelo, TX Junell Center, San Angelo, TX Junell Center, San Angelo, TX steel Corporation 19

19 SPECIAL SHAPES ENGINEERING WITH OPEN WEB STEEL JOISTS As a minimum, the dimensions and information shown in the sketches must be provided for joists with special profiles. Special shape joists do not to need to have a standard SJI designation. The load/span method, as described in this section, can be utilized for special shape joists with supplementary load diagrams, as shown in the special loads section. For joist lengths over 100 feet, a field bolted splice will likely be required for shipment in halves or thirds. Joist depths over 8 feet will require special shippping arrangements. When the total depth of the joist profile reaches 15-6, it cannot be shipped as a unit and some form of field assembly will be required. For any joist shipped in halves, thirds, or pieces, it is critical that the match-marked parts be joined. The parts are not interchangeable. Special consideration should be given to the camber of special joists, particularly where they are adjacent to other framing or deck supports. If Canam is provided with the actual design dead load, special camber can be provided. GABLE JOIST SCISSOR JOIST Idaho Sports Center, Nampa, ID steel Corporation 20

20 SPECIAL SHAPES ENGINEERING WITH OPEN WEB STEEL JOISTS Gable joists are commonly specified as bottom chord bearing, as shown in the sketch. The specifier should consider the use of the end walls as an anchorage point for the joist bridging, which is critical to provide lateral stability. Gable joists need not be symmetric. For any double pitched configuration, an offset ridge can be provided. Note that barrel and scissor joists are modeled with pin and roller supports and the truss will deflect horizontally. The specifier must make provisions to allow for this horizontal movement. Any special limitations on the amount of allowed horizontal deflection must be clearly shown on the contract drawings. To obtain the most economical design, Canam will vary the configuration of the joist web members within the overall profile provided in the sketch on the contract drawings. If a particular web geometry is required to create specific openings for mechanical needs, catwalks, or architectural reasons, these requirements should be noted with the profile, and specific dimensions locating the joist panel points should be provided. BOWSTRING JOIST R= BARREL JOIST R= R= Buckeye Fried Chicken, Columbus OH Buckeye Fried Chicken, Columbus OH steel Corporation 21

21 OSHA HIGHLIGHTS ENGINEERING WITH OPEN WEB STEEL JOISTS These pages summarize the key provisions of the revised OSHA steel erection standard, 29 CFR Part The complete OSHA rule for steel joists is included as an appendix to the Steel Joist Institute Specifications in this publication. The two most critical elements to the safe erection of steel joists are to limit or eliminate the need to walk un-bridged joists, and to properly and completely install the bridging as soon as possible. Canam advocates erection methods whereby the erector is not required to walk an un-bridged joist to release the hoisting cable. This can be accomplished by using erection stability bridging, working from a man-lift or other ground support, setting the joists in pre-assembled panels, or using a self-releasing mechanism on the crane. JOISTS AT COLUMNS Joists at column lines, which are not framed in at least two directions by solid web structural steel members, shall have a field-bolted connection at the joist bearing seat. In addition, joists at column lines must also have bottom chord extensions (BCX s). The BCX must extend to a vertical stabilizer plate. The stabilizer plate is to be a minimum size of 6 inches by 6 inches, with 3 inches extended below the bottom chord with a 13/16 inch hole to provide for a cable attachment. Where a steel joist does not lie directly along the column line, the joist nearest the column, on each side of the column, shall have field-bolted bearing seats. However, the bottom chord extensions may be omitted where it is not practical to provide them near the column. ERECTION STABILITY BRIDGING The forty foot rule no longer applies for the requirement of a bolted diagonal bridging line. The spans in the shaded portions of the Load Tables require a row of bolted diagonal bridging. Note that there are many designations and spans of less than forty feet that are shaded and require a row of bolted diagonal bridging. But there are also many designations and spans greater than forty feet which are not shaded and do not require a bolted diagonal bridging row. BOLTED BEARING SEATS Joists in bays of 40 feet or more shall be fabricated and installed with a field-bolted connection from the joist bearing seat to the steel frame. The bay length is the length from center to center of steel supports, or center of steel to face of wall. An exception to this rule is made for those cases where constructibility does not allow the bolted connection, or where multiple joists are pre-assembled and set in panels. Typically, the field-bolted bearing seat connection will be made with ASTM-A307 bolts in slotted holes and is considered a temporary connection. The final connection should be made by welding or as specified by the project structural engineer of record. COLUMN JOIST STABILITY The OSHA rules require that steel joists at or near columns that span 60 feet or less be designed with sufficient strength to carry the self-weight of the joists and the weight of one erector. This allows the hoisting cable to be released without the need for erection stability bridging. It is only possible to meet this column joist requirement if certain conditions are met, and these joists will be identified with the symbol OC on Canam s framing plans to show that they are OSHA column joists. In spite of this requirement, Canam advocates alternate erection methods that allow the hoisting cable to be released without an erector walking an unbridged joist. For the joists identified as OSHA column joists ( OC ) Canam will utilize a complex formula to check the erection stability. This check will conservatively assume that bottom chord extensions are not present to allow for the possibility of column joists that are near, rather than at, column lines and may not have BCX s. If the column joist does not initially pass the stability check, Canam will modify the joist design such that the joist will pass. Typically, this will involve increasing the joist top chord size. In order for a joist to be considered as an OC column joist, it must have standard parallel chords with standard under-slung bearing ends, and must have a slope of 1/4 inch per foot or less. In addition, the erector must secure both ends with two wrench tight bolts (or the equivalent for ends not at steel frames) and the joist must be placed plumb and true. For sloped, pitched, bottom bearing, or other special column joists, it will not be possible to apply the stability formula and check for erection stability. These column joists will be identified as DT joists on Canam s framing plans, and will be supplied with a Danger Tag hung on the joist to warn the erector that the joist has not been designed to support an employee without bridging installed, and alternate erection methods must be used. Beyond 60 foot spans, OSHA does not have special stability requirements for column joists. Column joists that span more that 60 feet should be set in tandem with all bridging installed or by the erector s alternate means of erection. steel Corporation 22

22 OSHA HIGHLIGHTS ENGINEERING WITH OPEN WEB STEEL JOISTS BUNDLE SIZES AND PLACEMENT Bridging bundles shall be limited to 1000 pounds maximum. The bridging bundle shall be placed across a minimum of three joists, within one foot of a secured end of the joists. Where Canam supplies metal decking, the deck bundles shall be limited to 4000 pounds maximum. The deck bundles should not be placed before the joist ends are attached and all bridging has been installed, except where the OSHA rule allows the deck bundle to be placed after only one row of bridging is installed and other special conditions are met. BOTTOM BEARING JOISTS Bolted diagonal bridging is required over or near the support for all bottom chord bearing joists. This includes both square-end joists, and cantilever-square-end joists. This is a general summary of the OSHA requirements, but is not intended to constitute legal advice. Canam does not assume responsibility for compliance with OSHA requirements. This is a sample Danger Tag which is hung on joists marked DT on the drawings. This block of notes will appear on all of Canam s framing plans. ERECTORS NOTE: ALL JOISTS IN BAYS WITH CENTER OF STEEL TO CENTER OF STEEL OR CENTER OF STEEL TO INSIDE FACE OF WALL OF 40-0 OR GREATER ARE TO BE BOLTED FOR ERECTION AT STEEL BEARING ENDS. THIS REQUIREMENT MAY BE WAIVED UNDER CERTAIN CONDITIONS. CONSULT THE OSHA SAFETY STANDARDS FOR SPECIFICS. THE FINAL CONNECTIONS ARE TO BE WELDED AS INDICATED ON THESE DRAWINGS. - COLUMN JOIST OR JOIST NEAR A COLUMN DESIGNATED AS (OC), SHALL NOT BE RELEASED FROM THE HOISTING LINE UNTIL THE JOIST IS DETERMINED TO BE PLUMB AND TRUE AND EACH END IS SECURED WITH AT LEAST TWO BOLTS OF THE SAME SIZE AND STRENGTH AS SHOWN ON THESE DRAWINGS, DRAWN UP WRENCH TIGHT OR EQUIVALENT. - IF A COLUMN JOIST IN BAYS 60-0 OR LESS IS DESIGNATED AS (DT): * THIS JOIST HAS NOT BEEN DESIGNED TO SUPPORT AN EMPLOYEE WITHOUT BRIDGING INSTALLED. * THIS JOIST IS NOT AN OSHA JOIST DESIGNED FOR STABILITY PER SUBPART R (3) DUE TO ITS SPECIAL PROFILE OR SLOPED CONDITION. * SPECIAL ERECTION METHODS MUST BE INCORPORATED. * DO NOT ALLOW EMPLOYEES ON THIS JOIST UNTIL ADEQUATELY STABILIZED. CONSULT THE OSHA SAFETY STANDARDS FOR SPECIFICS. - IN BAYS GREATER THAN 60-0, JOIST AT OR NEAR COLUMNS SHALL BE ERECTED IN TANDEM (PAIR) WITH AN ADJACENT JOIST. ALL BRIDGING MUST BE INSTALLED BEFORE LIFTING AND THE PAIR OF JOISTS MUST BE SECURED TO THEIR SUPPORT BEFORE RELEASING THE HOISTING LINE. THIS REQUIREMENT MAY BE WAIVED UNDER CERTAIN CONDITIONS. CONSULT THE OSHA SAFETY STANDARDS FOR SPECIFICS. steel Corporation 23

23 FLOOR VIBRATION ENGINEERING WITH OPEN WEB STEEL JOISTS Floor vibration has become a structural design issue due to the increased use of longer spans, more open areas and lighter floor systems. 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 to predict floor behavior and damping values for walking induced vibration have been established according to the type of wall partitions and floor finishes. These equations are now part of Steel Design Guide #11, jointly published by the American and Canadian Institutes of Steel Construction in This guide covers different types of floor vibrations and is one of the main references on the subject. The formulas shown in Steel Design Guide #11 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. Information about the use and architectural finishes of a building is not readily available to the joist supplier. The joist supplier usually receives only the floor drawings and general joist specifications and designation. This is the information that is used for joist design. Furthermore, when a project structural engineer has predetermined the design of a joist including spacing, depth, span, bearing support, and dead loads, the joist design alone cannot be easily modified to reduce floor vibration induced by walking below the annoyance threshold for the other occupants. The following example of this situation is for office floors where the annoyance threshold is defined as a floor acceleration of 0.5% of the gravity acceleration and with enough partitions to provide moderate damping. For floors in a shopping mall, 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. TYPICAL OFFICE FLOOR INITIAL DESIGN: In the example, the floor area is 90 by 96, the joists have a 30-0 (9 150 mm) span, a 20 (approx. 500 mm) depth, and are spaced at 4-0 (1 220 mm) on center. The joists are bearing on beams at both ends on 2 1/2 (65 mm) deep seats. The assumption is that the beams will be only partially composite for vibration calculations because of the relative lack of stiffness of such a bearing seat. The beam span is 24-0 (7 315 mm) with joists bearing from both sides and acts as a single span. The floor is made of a 4 (100 mm) concrete slab, including the 1 1/2 (38 mm) steel deck profile. The loads are as follows: Structural steel 5 psf (0.24 kpa) Steel joists 4 psf (0.19 kpa) Deck-slab of 100 mm 38 psf (1.82 kpa) Ceiling, mechanical & floor finish 10 psf (0.48 kpa) Partitions 20 psf (0.96 kpa) DEAD LOAD TOTAL 77 psf (3.69 kpa) LIVE LOAD 50 psf (2.40 kpa) From the SJI K-Series load table, select a joist with a 30-0 span to support the following loads: w = 4 x ( ) = 488 plf A joist with a 20K10 designation will support 533 plf for a 30-0 span and a uniform load of 336 plf will produce a deflection equal to the span of 360 which is fine since the live load is 200 plf. By reducing the simple span deflection formula under uniform load for span/360, we obtain the following approximation of the moment of inertia: I joist = W 360 x (span) 3 / 38,000, where I joist = moment of inertia in in. 4 w 360 = uniform load producing a deflection equal to span / 360 in. plf Span = span of joist in feet I joist = 336 x (30) 3 / 38,000 = 238 in. 4 The center of gravity of the joist steel cross section can be assumed to be at mid depth. A joist chords = I joist / (depth / 2) 2 = 2.38 in. 2 The beam can be chosen from the AISC selection tables as W18 x 60 with F y = 50 ksi and a moment of inertia of 984 in. 4. ALTERNATE 1: If a slab of 5 instead of 4 is used, the dead load increases and the size of the joists and beams may also increase. Structural steel 5 psf (0.24 kpa) Steel joists 4 psf (0.19 kpa) Deck-slab of 5 50 psf (2.40 kpa) Ceiling, mechanical & floor finish 10 psf (0.48 kpa) Partitions 20 psf (0.96 kpa) DEAD LOAD TOTAL 89 psf (4.27 kpa) LIVE LOAD 50 psf (2.40 kpa) From the SJI K-Series load table, select a joist with a 30-0 span to support the following loads: w = 4 x ( ) = 536 plf steel Corporation 24

24 FLOOR VIBRATION ENGINEERING WITH OPEN WEB STEEL JOISTS The same 20K10 joist will work for a 30-0 and the properties will be the same. I joist = 336 x (30) 3 / 38,000 = 238 in. 4 A joist chords = I joist / (depth / 2) 2 = 2.38 in. 2 This time, the beam chosen from the AISC selection tables is W18 x 65 with F y = 50 ksi and a moment of inertia of 1,070 in. 4. ALTERNATE 2: Starting from the base example, consider that the structural engineer of the building clearly indicates that the size of the joists should be doubled to reduce floor vibration. Since there are no standard K-Series joists with the same depth that are twice the size of a 20K10, we will double up the joists by spacing the 20K10 joists at 2 on center. ALTERNATE 3: Combining the changes of alternates 1 and 2, we evaluate a 5 slab on 20K10 joists spaced at 2-0 on center. Using the data of those 4 conditions, with the proposed equations of Steel Design Guide #11 and considering an open floor even if the structure is designed for a possible partition load, we obtain the vibration properties shown in the comparison table below: COMPARISON OF VARIOUS ARRANGEMENTS PARAMETERS INITIAL ALTERNATE 1 ALTERNATE 2 ALTERNATE 3 DESIGN INCREASED DOUBLE JOIST DOUBLE JOIST THICKNESS OF SAME SIZE OF SAME SIZE OF SLAB AND INCREASED THICKNESS OF SLAB Peak acceleration a o with open floor (% g) 1.11% 0.87% 0.81% 0.65% Peak acceleration a o with some partitions (% g) 0.74% 0.58% 0.54% 0.44% Peak acceleration a o with full height partitions (% g) 0.44% 0.35% 0.32% 0.26% System frequency f (Hz) Joist length (ft.) Joist depth (in.) Joist spacing (ft.) Joist moment of inertia (steel) (in. 4 ) Deck depth (in.) Slab-deck thickness (in.) Slab-deck-joist dead weight (psf) Additional participating load (psf) Beam size W18 x 60 W18 x 65 W18 x 60 W18 x 65 Beam span (ft.) This comparison shows that the vibration characteristics improve by adding dead weight or by doubling the joists. One must note that the alternates 1 and 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 shown as alternate 3 indicate that using a 5 deck-slab with a 100% increase in the joist sections would lower the peak acceleration 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 must 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 joists during the initial design. The project structural engineer 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 then verify conformance to the minimum moment of inertia required by the building designer for the joists. steel Corporation 25

25 ENGINEERING WITH OPEN WEB STEEL JOISTS JOIST SUBSTITUTES The Steel Joist Institute has introduced a joist substitute series, the 2.5K series. SJI load tables and specifications can be found on page 37 of this catalog. Joist substitutes are intended to be used for relatively short spans. It is more economical to use joist substitutes rather than joists for spans of 10 feet and under. Canam has extended the load tables to allow the specifier to make proper selection of joist substitutes. Joist substitutes are solid members made of angles, channels, or tube steel. SPAN JOIST SUBSTITUTES 2.5K1 2.5K2 2.5K3 S (in. 3 ) Mr (k-ft.) I (in. 4 ) Span (ft.) ALLOWABLE LOADS (plf) / / / / / / / / / / / / / / 71 The figures in red represent the maximum live load to create a L/360 deflection. If L/240 is acceptable, these figures can be multiplied by DESIGN SPAN 2 2 1/2 U.N.O. 4 MIN ON MASONRY 2 1/2 MIN ON STEEL Joist substitutes can be used in many conditions. They can be used in combination with LH-Series joists. In these cases, a deeper joist substitute will be supplied or seats will be installed on a regular 2 1/2 deep section as shown below. 5 Joist substitutes can be used on sloping roofs. Seat depth for sloped joist substitutes should be selected as per the table on page 13 of this catalog. steel Corporation 26