1. GENERAL

1.1 Related Work Specified in Other Sections

1) Section 06100: Rough carpentry.

2) Section 06125: Wood deck.

3) Section 06180: Glue Laminated Structural Units.

1.2 Reference Standards

1) Alberta Building Code ABC 1997

2) Engineering Design in Wood (Limit States Design) CSA-O86.1-94

3) Softwood Lumber CSA-O141-91

4) Standard Grading Rules for Canadian Lumber NLGA-1994

5) Truss Design Procedures and Specifications For Light Metal Plate Connected Wood Trusses TPIC-1996

1.3 Definitions

1) Truss Design Engineer is a P.Eng registered in the Province of Alberta who seals truss design drawings.

2) Truss Designer is either the Truss Design Engineer or a suitably qualified person working in conjunction with Truss Design Engineer.

3) "Commercial Certificate A" is a certificate held by a truss fabricator whose in plant Quality Assurance program is audited to assure that WWTA's Extended Quality Assurance requirements are met and who employs or retains a P. Eng. registered in the Province of Alberta to oversee the design and manufacture of wood trusses.

4) "Commercial Certificate B" is a certificate held by a truss fabricator whose in plant Quality Assurance program is audited to assure that WWTA's Extended Quality Assurance requirements are met and who employs a suitably qualified person to oversee the design and manufacture of wood trusses and who works in conjunction with an off site P. Eng. registered in the Province of Alberta, knowledgeable in the use of the truss design software program and is familiar with the truss fabricator's production facility.

5) "Member in Good Standing" is a WWTA of Alberta member whose plant has a Standard Quality Assurance program verified by third party inspections conducted at least twice per year.

1.4 Design Criteria

1) Design wood trusses, bracing, bridging and connectors in accordance with TPIC and CSA-O86.1.

2) Design wood trusses to resist the specified loads including any build up and/or drift loading as shown on the structural drawings for the building.

3) Girder truss locations that are shown on the building structural drawings shall not be relocated without the approval of the Structural Engineer of Record.

4) Design wood trusses to accommodate mechanical ducting when cavity dimensions are shown on the building structural drawings.

5) Serviceability requirements for wood trusses are as listed in Table 4.5.1. (4) of TPIC unless specifically indicated on the drawings.

1.5 Wood Truss Drawings

1) Wood truss fabricator shall submit truss design drawings prior to fabrication for approval by the Structural Engineer of Record.

2) The final truss design drawings shall bear the stamp of a qualified professional engineer registered in the Province of Alberta.

3) Truss design drawings shall indicate as a minimum the following information:

a) Truss identification number and job name,

b) Span, depth or slope and spacing of trusses,

c) Size, species and grade of lumber used for each truss member;

d) Required bearing widths,

e) Specified loads as applicable: top chord live load, top chord dead load, bottom chord live load, bottom chord dead load, concentrated loads and their points of application, controlling unbalanced, wind and earthquake loads.

f) Location, size and fastening of any required permanent truss member bracing,

g) Reactions forces, their points of occurrence and direction,

h) Adjustments to lumber and metal connector plate design values for condition of use,

i) Metal connector plate type, gauge, size and location of plate at each joint, except where symmetrically located relative to the joint interface,

j) Connection requirements for (unless shown on the truss layout drawing): truss to bearing, truss or girder ply to ply, field splices.

1.6 Truss Placement and Layout Drawing

1) Wood truss fabricator shall submit truss layout drawing(s) with the truss design drawings for approval by the Structural Engineer of Record.

2) Shall indicate the location of each truss and girder by using the identification number shown on the truss design drawings.

3) Shall identify all walls that were taken as bearing walls.

4) Shall indicate the hanger type to be used for connecting trusses to girder trusses and beams.

5) Connection requirements for (unless shown on the truss design drawings): truss to bearing, truss or girder ply to ply, field Splices

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