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BCSI 06 For information on: Jobsite storage Truss handling

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1 BCSI 06 For information on: Jobsite storage Truss handling
Temporary bracing Fall protection Construction loading

2 Contents B1 – Handling, Installation and Bracing
B2 – Installation and Bracing B3 – Web Bracing/Reinforcement B4 – Construction Loading B5 – Damage, Modifications and Errors B6 – Gable End Frame Bracing B7 – Parallel Chord Trusses B8 – Toe-nailing for Uplift B9 – Multi-Ply Trusses B10 – Post Frame Trusses B11 – Fall Protection The presentation will discuss the contents of the BCSI Booklet.

3 Development of BCSI Engineers Manufacturers Suppliers Contractors
To that end, the Wood Truss Council of America and the Truss Plate Institute developed and produced the BCSI 1-03 Guide to Good Practice with input from dozens of industry engineers, component manufacturers, suppliers, and contractors. The booklet was released in October 2003. Suppliers Contractors

4 BCSI Booklet Replaces…
The BCSI booklet is a direct replacement for the HIB-91 Booklet from TPI. Many component manufacturers use the BCSI booklet as a desk reference or provide copies to regular customers. It is not necessary to include them in jobsite packages. HIB-91 Booklet

5 BCSI B-Series The 93-page BCSI booklet contains ten sections developed to assist truss installers in the variety of details involved in the proper handling, installing, restraining and bracing of trusses. The ten sections are broken into individual “B-Series” summary documents. Each summary sheet version is a concise, economical version of the booklet information but in a format more suitable for inclusion in jobsite packages.

6 BCSI B-Series Replaces...
HIB-98 Poster HIB-91 Sheet The B-Series Summary Sheets were developed to contain both English and Spanish text. The B-series replaces the former jobsite bracing guides such as TPI’s HIB-91 Summary Sheet, the HIB-98 Post Frame Truss Poster the WTCA-B1 Warning Poster and the TTB WTCA-B2 on Temporary Bracing. In addition, several of WTCA’s Truss Technology in Building brochures have been modified and re-introduced as part of the B-series documents. Now let’s go through the eleven B-series documents, starting with B1… WTCA-B1 Warning Poster TTB WTCA-B2

7 B1 Guide for Handling, Installing & Bracing
Consequences of improper installation may be collapse of the structure Section B1 The Guide for Handling, Installing and Bracing of Metal Plate Connected Wood Trusses The purpose of this section is to give a “big picture” view of how to properly store, handle, install and brace wood trusses, thereby improving jobsite safety and truss performance. It provides general information on the most important topics but relies on the succeeding B-series to get into the specifics.

8 B1 Summary Sheet WTCA-B1 Warning Poster HIB-91 Sheet
The B1 Summary Sheet replaces the HIB-91 Summary Sheet and the WTCA B1 Warning Poster. The B1 Summary Sheet presents the BCSI-B1 section in a one-page, 11x17 poster format (other poster sizes will be available). It is a full color, English/Spanish document that summarizes the main points of B1. It is blank on one side for printing Truss Placement Diagrams. WTCA-B1 Warning Poster HIB-91 Sheet

9 B1 Banding Warning

10 B1 Handling

11 B1 Handling

12 B1 Storage

13 B1 Storage

14 B1 Hand Erection

15 B1 Hoisting

16 B1 Hoisting Recommendations
From BCSI Booklet

17 B1 Hoisting Recommendations
From BCSI Booklet

18 B1 Hoisting Recommendations
From BCSI Booklet

19 B1 Bracing Warning

20 B1 Ground Bracing

21 B1 Top Chord Bracing See TCTLB Table

22 B1 Bottom Chord Bracing

23 B1 Web Plane Bracing

24 Lateral brace splicing
Look for “Truss Brace Splicing Methods” in the November SBC Magazine

25 B1 PCT Bracing (PCT)

26 B1 Diagonal Bracing

27 B1 Truss Installation

28 B1 Constructions Loads

29 B1 Construction Loads

30 B1 Alterations

31 B2 Truss Installation & Temporary Bracing
The second section, B2, focuses on Truss Installation & Temporary Bracing. It replaces the Truss Technology in Bracing Document WTCA-B2 on temporary bracing.

32 B2 Scope From p.8:

33 B2 Scope B2 Doesn’t Cover These 3x2 or 4x2 Flat Trusses
Trusses spaced > 2 ft. o.c. From p. 8 From p. 8

34 B2 Warnings

35 B2 Top Chord Bracing Ground bracing not shown
Take special care with spans over 60 ft.

36 B2 Checklist

37 B2 Steps to Setting Trusses

38 B2 Step 2 - Ground Braces

39 B2 Step 3 - Set First Truss

40 B2 Step 4 - Next 4 Trusses

41 B2 Step 4 - TCTLB Options

42 B2 Note on Bracing Materials

43 B2 Step 5 - Top Chord Diagonals

44 B2 Step 5 - Top Chord Sheathing

45 B2 Step 6 – Web Bracing

46 B2 Step 6 – High End Trusses

47 B2 Step 7 – Bottom Chord Bracing

48 B2 Step 8 – Repeat Groups of 4

49 B2 Sheath Early and Often

50 B2 Alternate Installation Method

51 B2 Special Conditions

52 B3 Web Member Permanent Bracing/Web Reinforcement
B3 Web member Permanent Bracing and Web Reinforcement replaces two Truss Technology in Building Brochures by the same name.

53 B3 Compression Web Members
Unstable if unrestrained Check Design Drawing if restraint req’d

54 B3 Bracing vs. Reinforcement
Bracing provides lateral support, reducing buckling length Reinforcement increases cross-section, making web more stable

55 B3 Six Methods of Restraint
These items apply to all six methods:

56 B3 CLBs and Diagonals

57 B3 CLBs and Diagonals

58 B3 CLBs and Diagonals

59 B3 T-Reinforcement

60 B3 L-Reinforcement

61 B3 Scab Reinforcement

62 B3 Metal Reinforcement

63 B3 Stacked Webs

64 B3 Gable End Frame Bracing
The Summary Sheet for B6 on Gable End Frame Bracing contains new information that was not previously published as a TTB.

65 B3 Gable End Frames Designed to transfer vertical loads
But may also experience lateral loads Sheathing, bracing and connections must be designed for this transfer Gable end frames contain vertical members arranged like flat studs. They are designed to transfer vertical loads from the roof to the gable end wall. Any lateral loads must be transferred by permanent bracing.

66 B3 Load Transfer Path There are number of factors that go into a properly designed system, but the goal is to get the lateral loads transferred safely into the upper and lower diaphragms. Some of items necessary to achieve this are specified by the Truss Designer and some are specified by the Building Designer.

67 B3 Poorly Designed System
Weaknesses in an un-designed, or under-designed, system probably won’t be evident until a temporary high load event. Here the high wind forces hit the unreinforced gable end frame and cause it to bow. The high lateral loads overcome the connection between the gable end frame and the wall, creating a hinge joint and the unblocked, undersized ceiling diaphragm buckles.

68 B3 Design Considerations
Gable End Frame Reinforcement prevents failure of individual vertical webs Frame to End Wall Correct connection prevents hinge joint Bracing, blocking and diaphragm design creates safe load path Some items that must be addressed in order to prevent these types of failures are the Gable End Frame itself it must be reinforced so that the individual vertical members do not fail when they receive these lateral loads. The Truss Designer may specify this reinforcement. More on this in a minute… Then the Frame–to–End Wall connection must be designed to resist loads between each other and the upper and lower diaphragms. This is the Building Designer’s responsibility and requires design of the lateral bracing system, thickness and type of sheathing, fastener schedules and all lateral load transfers.

69 B3 Bracing and Blocking This example shows a horizontal reinforcement (in red) and a diagonal brace (in purple) extending to roof diaphragm blocking. This requires proper design and specification of the diaphragm materials and fasteners, so it clearly is a Building Designer, not a Truss Designer, responsibility.

70 B3 Bracing and Blocking This option shows bottom chord bracing and blocking when there is no directly applied gypsum board ceiling. It also shows an alternative to the diagonal brace in the previous example. This diagonal brace in red extends from the gable end wall up to the roof diaphragm.

71 B3 Gable End Reinforcement
Horizontal reinforcement: In order to address the instability of the vertical members in the gable end frame, the Truss Designer may specify a horizontal reinforcement member.

72 B3 Gable End Reinforcement
Individual L- or T-reinforcements Or the Truss Designer may specify individual reinforcement of vertical members using L- reinforcements or T-reinforcements.

73 B3 Gable End Reinforcement
Scab reinforcements Or the Truss Designer may specify individual reinforcement using scabs, as in this case of structural gable end. In all cases, the Building Designer must still address how the lateral load will be transferred to the rest of the structure.

74 B3 Building Designer Detail
Here is an example of a well designed gable end bracing detail from a set of structural plans.

75 B3 Building Designer Detail
Among other things, notice the gable end frame is well connected to the end wall.

76 B3 Avoid Hinge Joint Balloon Framed End Wall
Here is one design strategy for avoiding the hinge joint between a gable end frame and the end wall. The wall studs are balloon framed, meaning they are continuous through the top plate and extend to the roof line.

77 B3 Scissor Truss End Wall
Scissor trusses must have a rake wall framed to the ceiling line in order to properly transfer loads into the ceiling diaphragm. A standard flat bottom gable end frame in this situation may lead to serviceability problems.

78 B3 Avoid hinge points in walls!
Additional Note: This wall will not meet the prescriptive method criteria under IRC for a braced wall.

79 B4 Construction Loading
B4 Construction Loading replaces the Truss Technology in Building Brochure by the same name.

80 B4 Construction Loads

81 B4 Loading DOs and DON’Ts

82 B4 Loading DOs and DON’Ts

83 B4 Loading DOs and DON’Ts

84 B4 Loading DOs and DON’Ts

85 B4 Loading DOs and DON’Ts
B4 Construction Loading replaces the Truss Technology in Building Brochure by the same name.

86 B4 Loading DOs and DON’Ts

87 B4 Loading DOs and DON’Ts

88 B4 Loading DOs and DON’Ts

89 B5 Truss Damage, Modifications and Installation Errors
B5 Truss Damage, Jobsite Modifications and Installation Errors replaces the Truss Technology in Building Brochure on Truss Repairs

90 B5 Truss Damages

91 B5 Steps for Repair

92 B5 Repair Techniques

93 B5 Report Damage

94 B5 Truss Repair Detail

95 B6 Section B6 used to be on Gable end bracing that information has now moved to section B3. B6 is intended to be used for additional topics in future additions of BCSI

96 B7 Parallel Chord Trusses
The Summary Sheet for B7 Temporary and Permanent Bracing for Parallel Chord Trusses contains new information that was not previously published as a TTB.

97 Guidelines for 3x2 or 4x2 only
B7 Lumber Orientation Guidelines for 3x2 or 4x2 only For 2x_ orientation see BCSI-B2 Parallel Chord or Flat Trusses are any trusses that have tops and bottom chords at the same pitch. They are most often installed in flat roof or floor applications. These bracing and handling recommendations are for trusses with lumber oriented in the flat-wise direction, such as 3x2 and 4x2 trusses. Most often, floor trusses are built in this fashion. Flat trusses built with lumber oriented in the 2x_ direction are not covered in the B7 section, see the BCSI-B2 summary sheet for handling, bracing and installing guidelines for these types of trusses.

98 B7 PCT Bearing Top Chord Bearing trusses can be more stable during installation due to their center of gravity below the bearing surface, but all trusses should be braced before installation crews walk on them.

99 B7 Temporary Bracing Trusses in the 3x2 and 4x2 orientation are more stable than their 2x_ counterparts but still require bracing as outlined here.

100 B7 Stabilize Truss Ends Temporary Bracing or Permanent Blocking
Stabilize truss ends by installing the temporary bracing or permanent truss end blocking at the outset.

101 B7 Correct Placement Parallel Chord Trusses can easily be placed upside down or wrong end-to-end. It is important to make sure they are installed correctly especially when the trusses may have interior bearings.

102 B7 Truss Tags Some truss manufacturers mark trusses with these tags to avoid mis-installations on the jobsite.

103 B7 Strongback Bridging Helps limit deflection and/or vibration
Truss manufacturers recommend the installation of strongback bridging. Most fire rated assemblies require strongback bridging. At a minimum, it should be a 2x6 installed vertically at the bottom chord, every 10 feet on center. If there is no vertical web on which to attach the strongback, install a vertical block for this purpose, as shown in Fig. B7-11.

104 B7 Construction Loads on PCT
Follow the same precautions as outlined in section B4. Parallel Chord Trusses often see more construction loads because they provide a flat working surface. Be careful not to overload truss. Brace the trusses before applying any loads. Don’t overload single trusses, spread over as many trusses as possible.

105 B8 Toe-Nailing for Uplift
The Summary Sheet for B8 Toe-Nailing for Uplift Reactions replaces the TTB of the same name.

106 B8 Uplift Forces The first example shows a truss subjected to wind uplift forces, in this case, both truss bearings will have to be designed for the uplift forces. The second example shows a off-center intermediate bearing truss under normal gravity loads. The exterior end of the shorter span will be subjected to uplift forces which create a “reverse deflection”. In this load case, the left side truss to bearing will have to be designed to account for uplift.

107 B8 Toe-Nailed Connections
Are three toe-nails enough? Many wood trusses are connected to the top plate using three toe-nails as shown here. Is this enough resistance for the design uplift forces? It depends on a three things…..

108 B8 1- Proper Toenail Installation
This diagram shows proper toe-nail installation. Toenail resistance is reduced by 33% as compared to straight nailing. If the toe-nail is not installed properly the actual reduction could be even larger.

109 B8 2- Top Plate Lumber Grade and species
Denser grades and species of top plates provide greater uplift resistance for toe-nails.

110 B8 3- Type of Nails Nail capacities are related to their shape and diameter. Listing just the pennyweight of a nail such as 10d, 16d, etc. is not descriptive enough to determine the capacity of the nail. That is why many Building Designers avoid confusion by calling out the diameter and length of the nail. 0.162″ x 3.5″

111 B8 Is Toe-Nailing Enough?
Toe-nail values must exceed expected uplift For example: A 16d common in a Southern Pine top plate offers 72 pounds of uplift resistance. 72 If there are three toe-nails, the total uplift resistance Is 3x72=216 pounds This chart lists several types of nails frequently used on construction sites. Choose a nail type for the proposed connection. Look in the column for the top plate species to see the nail uplift value. Multiply this value by the number of nails in the connection. Then…..

112 B8 Load Duration Factors
The values for the uplift capacities can be adjusted using these load duration factors. Just be sure you understand how to apply these factors and under what circumstances to use them. For wind uplift condition, most geographical areas (except high wind areas like Florida) will use the factor of 1.6. The factored uplift resistance of the toe-nails is then 216x1.6=346 pounds For wind uplift resistance use the factor of 1.6. Therefore, 216x1.6 = 346 pounds

113 B8 Alternatives to Toe-Nailing
Check published uplift capacities of mechanical connectors If the toe-nail resistance is not sufficient or the building codes requires a minimum mechanical connector, check the connector manufacturer’s specs to make sure the product meets or exceeds the expected design uplift force.

114 R802.10.5 Truss to wall connection
Trusses shall be connected to wall plates by the use of approved connectors having a resistance to uplift of not less than 175 pounds (79.45 kg.) and shall be installed in accordance with the manufacturer's specifications. For roof assemblies subject to wind uplift pressures of 20 pounds per square foot (0.958 kN/m2) or greater, as established in Table R301.2(2), adjusted for height and exposure per Table R301.2(3), see section R

115 IRC R The code requirement was added in the IRC 2003 in a perhaps well-intentioned effort to address a perceived issue from the proponent's point of view. Now that it is in the code, it is proving difficult to remove.  A number of code jurisdictions have amended the language or struck the language out of their code adoption. The 175 lb value is unrelated to any real design parameters or linked to any truss length. It arbitrarily discriminates against one well respected construction method. No specific evidence was or can be provided to justify this requirement.

116 IRC R TPI 1 requires that a Truss Design Drawing include reaction forces and directions, which would include a value for uplift based upon the structure's design parameters for wind. There is no valid reason for not using this calculated value in the consideration of the uplift connection requirements.

117 IRC R802.10.5 Much of the US is in the 90 mph basic wind speed zone.
The resistance for uplift, beyond the prescriptive fastening requirements of Table R602.3(1) is really seldom an issue, especially for structures categorized as Exposure B and with a Mean Roof Height of less than 30 feet. IRC Table R301.2(2) is used to trigger the need for special connection requirements per Table R Only high wind speed areas, highly exposed structures or extremely tall structures ever qualify for the special requirements. When the calculated uplift requires a connection of a specific value, WTCA supports providing resistance in a manner acceptable to the EOR or building code official, not based upon an arbitrary requirement.

118 B9 Multi-ply Girders The Summary Sheet for B9 Multi-Ply Girders replaces the TTB of the same name.

119 B9 Girders 4-ply 5-ply Designed to carry extra loads
Max. 6 plies, fastened together to act as one 4-ply 5-ply Multi-ply trusses are comprised of identical trusses fastened together to act as one. Girders can be up to a maximum of six plies depending on the truss layout and loading configuration.

120 B9 Fastener Schedule SAMPLE Specified on Truss Design Drawing
The fastening method is indicated on the girder truss design drawing.

121 B9 Nail Fasteners Fasteners using nails only are specified on girders with three plies or less Nails can be used on girders with up to three plies. The edge distances shown are a general recommendation based on information published the National Design Specification for Wood Construction from the American Forest & Paper Association.

122 B9 Screw Fasteners Special screws on up to four plies
Specially designed high strength screws may be specified for girders with up to four plies.

123 B9 Screw Fasteners Screws on 2-ply 3x or 4x2 floor-type trusses
These high strength screws can also be used on 4x2 or 3x2 floor girder trusses.

124 B9 Bolt Fasteners Bolts on 4 to 6 plies
In addition, nails may also be required Bolts are required on four to six plies. The fastener schedule may indicate that additional nails are alo required.

125 B9 Good Installation Practices
Fasten plies together before lifting, if possible A good practice is to fasten all the plies together before lifting into place and installing.

126 B10 Post Frame Trusses HIB-98 Poster
The Summary Sheet for B10 Post Frame Truss Installation and Bracing replaces the TPI poster called HIB-98 Post Frame Summary Sheet. HIB-98 Poster

127 B10 Post Frame Trusses Part of an engineered building system
Spaced at 4′ to 12′ o.c. Heels attached to posts fixed in ground or slab Purlins attached directly to truss top chords

128 B10 Truss Storage

129 B10 Installation

130 B10 Installation

131 B10 1- Ensure Stable Columns

132 B10 2- Stable Base Unit

133 B10 3- Bracing of Base Unit Top Chord
A professional engineer should design a bracing plan for truss spans over 60’ per BCSI Fig.B2-13

134 B10 3- Bracing of Base Unit Bottom Chord

135 B10 3- Bracing of Base Unit In the Roof Plane - or -

136 B10 3- Bracing of Base Unit In the Web Plane

137 B11 Fall Protection & Trusses
The Summary Sheet for B11 Fall Protection and Wood Trusses replaces the TTB of the same name.

138 B11 Fall Protection Warning
Trusses alone are not designed to support fall protection anchors

139 B11 Impact Loads A falling worker could cause the trusses to collapse in a domino effect

140 B11 Safer Options Option 1: Scaffolding

141 B11 Safer Options Option 1: Roof Peak Anchor

142 B11 Safer Options Option 1: Ground Assembly

143 Jobsite Safety Package
B1 through B4 Handling Checklist The pre-assembled WTCA/TPI jobsite package contains summary sheets B1 through B4.

144 Truss Tags

145 Questions on BCSI?

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