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Welcome to the Atlantic Wood Truss Fabricators Association web page. The AWTFA was formed in 1986 and has a current membership of approximately 30 members. The membership consists of both truss fabricators and Associate members such as plate suppliers and lumber dealers. The Association has members in every Atlantic Province and take great pride in assuring the general Public that our member companies consist of highly qualified professional people trained in the latest software of truss design and pre-engineered wood products. These companies supply trusses and related products to the residential and commercial industries throughout the entire region and into the United States.

The structure of our Association consists of a President, Past- President, Vice- President, Secretary, Executive Director, Associate Director and a Director from each Province. We have representation on the Canadian Wood Truss Fabricators Association and the Truss Plate Institute Of Canada, these affiliations allow are members to benefit and participate in a full range of issues such as building code changes, insurance rates, health and safety and quality control in our member plants.

We have a general meeting and election of officers annually which is held in one of the four Atlantic Provinces and have hosted are first annually golf tournament in 2001 in PEI. These events give are members the opportunity to exchange ideas and socialize with members and potential members from the entire region.

I hope you find our web page informative and appreciate any feed back you may like to make to our Association.

Click Here Meet the Board of Directors.

Objectives

  1. Develop and establish uniform standards for the design, manufacture, and quality control of prefabricated wood trusses.
  2. Promote the interest of prefabricated wood trusses and engineered wood products to all levels of government
  3. Stay in contact with all the different aspects of dealing with building codes and standards
  4. Foster the acceptance of prefabricated wood trusses for use in residential, farm, commercial, and industrial buildings by architects, engineers and the general public
  5. Keep the members aware of all pertinent information and new developments in the truss industry.


AWTFA
Atlantic Wood Truss Fabricators Association

CODE OF STANDARD PRACTICE

FOR WOOD TRUSS MANUFACTURERS

PREFACE

The purpose of this Code is to encourage a uniform performance of the AWTFA members and to promote a clear understanding between AWTFA members, the specifying community, erection industry and its clients. The Code covers all facets of the truss development process from design to proper installation, the Overall Job Process (OJP). We endeavor to define the performance of areas in the OJP that are under our control such as component design, manufacturing, marking, documentation and delivery; and to positively influence the other parts of the OJP that we don’t fully control, such as the product specification and installation.

The Code is a compilation of usual industry practices relating to the design, fabrication and erection of wood trusses. These practices will evolve over a period of time and will be subject to change as improved methods replace those of today. 

Adopted on: January 25, 2003

1. GENERAL PROVISIONS

1.1 Scope 

This Code covers standard industry practice for wood truss manufacturing for trusses to be shipped within the Atlantic region. In the absence of provisions to the contrary contained in contracts to which members of the AWTFA are contracting parties, members will abide by the practices described herein.


1.2 Definitions

BD stands for Building Designer who is the person having the ultimate responsibility for the overall design of the building. In some cases the BD is also the Structural Engineer of Record and vice versa.

Commercial is a job conforming to the Part 4 of the Building Code of the province in which the project is being built.

Farm is a job conforming to the National Farm Building Code of Canada

GC stands for General Contractor

Member in Good Standing (MGS) is the AWTFA member who follows the objectives of the AWTFA, the code of ethics and keeps their dues current

Off site P.Eng is a Truss Design Engineer most commonly employed by or on contract to a connector plate supplier who works in conjunction with the truss manufacturer’s design personnel but not on the same premises.

OJP stands for Overall Job Process and consists of six parts: Specification, Bidding, Contract, Manufacturing, Installation and Inspection.

Residential is a job conforming to Part 9 of the Building Code of the province in which the project is being built.

SER stands for Structural Engineer of Record.

TD stands for Truss Designer who is either the Truss Design Engineer or a suitably qualified person working in conjunction with Truss Design Engineer.

TDE stands for Truss Design Engineer who is a P.Eng registered or licensed in the Province in which the project is being built who seals truss design drawings.

1.3 Responsibilities
1.3.1 Structural Engineer of Record or Building Designer

1.3.1.1 Responsibility of Building Designer (BD) - commercial. The BD provides the following information to the Truss Designer (TD) or Truss Design Engineer (TDE):

  • Completed set of dimensioned drawings.
  • Bearing points for all trusses.
  • Building layout outlining girder truss locations and bearing points.
  • Point load values and locations.
  • Building elevations.
  • Loading diagrams, including built-up loads from snow drifts.
  • Code requirements.
  • Outline stamping requirements of the truss drawings.
1.3.1.2 Responsibility of Building Designer (BD) - residential. The BD provides the following information to the TD or TDE:
  • Completed set of dimensioned drawings.
  • Building elevations.
  • Geographical location of the building and or ground snow load required.
  • Code requirements.
  • Outline stamping requirements of the truss drawings.
1.3.1.3 Responsibility of BD – farm. The BD provides the following information to the TD or TDE:
  • Completed set of dimensioned drawings.
  • Building elevations.
  • Geographical location of the building and ground snow load required.
  • Wind conditions on site – swept or unswept.
  • Code requirements.
  • Outline stamping requirements of the truss drawings.
1.3.2 Responsibility for design

1.3.2.1 Responsibility for design - commercial. When the BD provides specifications (as per 1.3.1.1) or approves drawings, the truss manufacturer shall not be responsible for determining the adequacy of the building design or structure, nor liable for the loss or damage resulting from an inadequate design. Even though proposed component design and design details may be prepared by the truss manufacturer’s technical staff the overall behavior of the structure remains the responsibility of the BD. The BD is responsible for determining the temporary and permanent truss bracing requirements for the structure.

1.3.2.2 Responsibility for design - residential. When the BD provides specifications (as per 1.3.1.2) or approves drawings, the truss manufacturer shall not be responsible for determining the adequacy of the building design or structure, nor liable for the loss or damage resulting from an inadequate design. Even though the proposed component design and design details may be prepared by the truss manufacturer’s technical staff the overall behavior of the structure remains the responsibility of the BD. When the TD or TDE determines the bearing points for all trusses, building layout outlining girder truss locations and bearing points, point load values and locations and loading diagrams including built-up loads from snow drifts he will follow the appropriate sections of Part 9 of the applicable Provincial Building Code and submit these for approval to the BD. The BD is responsible for determining the temporary and permanent truss bracing requirements for the structure.

1.3.2.3 Responsibility for design - farm. When the BD provides specifications (as per 1.3.2.3) or approves drawings the truss manufacturer shall not be responsible for determining the adequacy of the building design or structure, nor liable for the loss or damage resulting from an inadequate design. Even though the proposed component design and design details may be prepared by the truss manufacturer’s technical staff the overall behavior of the structure remains the responsibility of the BD. When the TD or TDE determines the bearing points for all trusses, building layout outlining girder truss locations and bearing points, point load values and locations and loading diagrams including load conditions due to wind and built-up loads from snow drifts he will follow the appropriate parts of the National Farm Building Code of Canada and submit these for approval to the BD. The BD is responsible for determining the temporary and permanent truss bracing requirements for the structure.

1.3.3 Responsibility for installation

1.3.3.1 Responsibility for installation procedure. When the installation of trusses is part of his contract, the truss manufacturer shall be responsible for determining the installation procedure, for checking the adequacy of the connections for the uncompleted structure and for providing installation bracing or connection details. When the installation of wood trusses is not part of this contract, the truss manufacturer shall not be responsible for the uncompleted structure, or for providing erection bracing or connection details not included in the contract documents, nor shall the truss manufacturer be liable for loss or damage resulting from faulty installation. However the truss manufacturer shall be informed by the client of the installation sequence to be used when it influences the sequence and process of the manufacturing.

1.3.3.2 Materials included. Unless otherwise specified in the tender documents, a contract to supply and fabricate wood trusses shall include only those items from the following list which are clearly indicated as being required by the structural drawings and tender specifications:
  • wood trusses
  • connecting hardware – truss to product supplied by plant i.e. truss, beam
  • bearing hardware (hangers) – truss to product supplied by plant i.e. truss, beam
1.3.3.3 Field connection material included. When the truss manufacturer installs the truss system, unless otherwise specified, he shall supply all the material required for temporary and for permanent bracing of the trusses in the system.

1.3.3.4 Field connection material not included. When installation of the truss system is not part of the truss manufacturer’s contract, unless otherwise specified, the truss manufacturer shall furnish only the appropriate special fasteners of suitable size and in sufficient quantity for all field connections which are specified to be thus permanently connected. Unless otherwise specified in the tender documents the blocking and bracing material for the truss system shall not be furnished by the truss manufacturer. 

2. SPECIFICATION

2.1 The shop drawings for trusses and other structural wood products supplied by members shall be produced to the specifications provided by the BD or his SER and communicated to fabricators by the General Contractor (GC) (See 1.3.1) 

2.2 In case the specifications are incomplete, the fabricator contacts the GC who may have to obtain them from the BD or his SER and pass them on to fabricator.

2.3 Typically the flow of information should be from the fabricator to the GC and from GC to the BD or his SER and vice versa unless otherwise agreed on between the parties involved.

3. BIDDING

3.1 Unless otherwise specified in the tender documents the bid will include only items identified in 1.3.3.2.

3.2 Unless the truss manufacturer installs the truss system the field connection material as per 1.3.3.4. is not included in the bid.

3.3 Unless otherwise specified in tender documents on-site inspection is not included in the bid. 

4. CONTRACT

4.1 Standard Form of Contract. Unless otherwise agreed upon, a contract to fabricate, deliver and/or install trusses shall be based on the appropriate Standard Construction documents approved by the Canadian Construction Documents Committee, or the Canadian Construction Association.

4.2 Revisions of Contract Documents.

4.2.1 Revisions to the contract shall be made by the issue of dated new or revised documents. All revisions shall be clearly indicated. Such revisions may be issued on a Detailed Change Notice.

4.2.2 The truss manufacturer shall advise the client or client representative of any impact such revision shall or change will have on the existing agreement between the two parties.

4.2.3 Upon agreement between the truss manufacturer and the client or client representative as to revision’s impact, the client or his representative shall issue a change order or extra work order authorizing the truss manufacturer to proceed with the work.

4.2.4 Unless specifically stated to the contrary, the issue of a revision is authorization by the client to approve these documents for construction.

4.3 Contract price adjustments.

4.3.1 When the responsibility of the truss manufacturer is changed from that previously established by the contract documents, an appropriate modification of the contract price shall be made. In computing the contract price adjustment, the truss manufacturer shall consider the quantity of work added or deleted, modifications in the character of the work, the timeliness of the change with respect to the status of material ordering, the detailing, fabrication and related impact costs.

4.3.2 Requests for contract price adjustments shall be presented by the truss manufacturer and shall be accompanied by a description of the change in sufficient detail to permit evaluation and prompt approval by the client. 

5. MANUFACTURING

5.1 Design procedures

5.1.1 Design work

5.1.1.1 Truss take-off shall be prepared from the most recent version of the building plans. All trusses shall be identified and subsequently marked clearly so that the markings on trusses correspond with the markings on the truss placement layout, when provided.

5.1.1.2 TD shall advise the SER or the BD, whatever the case may be, through GC, about all changes to be made to accommodate the trusses (such as but not limited to special bearing conditions for girders, transfers of loads, additional beams, changes to truss directions, etc.).

5.1.2 Design criteria

5.1.2.1 Commercial. The design shall conform to the current applicable provincial building code, TPIC design procedures, CSA/CAN3-086.1-94, and local codes or any other codes currently in force. Truss design drawings shall be sealed by TDE when requested by the SER or an authority having jurisdiction.

5.1.2.2 Residential. The design shall conform to the current applicable provincial building code, TPIC design procedures, CSA/CAN3-086.1-94, and local codes or any other codes currently in force. Truss design drawings shall be sealed by TDE when requested by the SER or an authority having jurisdiction.

5.1.2.3 Farm. The design shall conform to the National Farm Building Code of Canada, TPIC design procedures, CSA/CAN3-086.1-94 and local codes or any other codes currently in force. Truss design drawings shall be sealed by TDE when requested by the SER or an authority having jurisdiction.

5.1.2.4 Commercial and farm designs can only be considered windswept if the SER so specifies. In case the SER is not retained, roof truss live load shall no be less than 60% of ground snow load at any time.

5.1.3 Truss design drawings

5.1.3.1 A truss design drawing shall be prepared for every truss manufactured and identified by markings corresponding with those on the layout drawing. 

5.1.3.2 The truss design drawing shall include reference to the design criteria used, lumber requirements, plating requirements, design loading, spacing, special framing details, bracing details and nailing, framing instructions and adjustment to plate and design values.

5.1.3.3 Truss design drawing shall indicate as a minimum the following information:
  1. Truss identification number and job name;
  2. Span, depth or slope and spacing of trusses;
  3. Size, species and grade of lumber used for each truss member;
  4. Required bearing widths;
  5. 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
  6. Location, size and fastening of any permanent truss member bracing:
    • continuous bracing for three or more adjacent trusses of the same kind
    • “T” bracing for one or two trusses of the same kind
  7. Reaction forces, their points of occurrence, direction and support conditions 
  8. Adjustments to lumber and metal connector plate design values for condition of use;
  9. Metal connector plate type, gauge, size and location of plate at each joint interface;
  10. Connection requirements for (unless shown on truss layout drawing):
    • truss to bearing
    • truss to girder or beam
    • truss to girder ply to ply
    • field splices.
  11. Deflection limits, deflection and CSI
  12. Code used (Residential, Commercial, Farm)

5.1.3.4 Truss layout drawing includes truss designations, their placement, bearing conditions and special hardware.

5.2 Approval
5.2.1 Commercial. Truss manufacturers submit the truss design drawings to the GC, who reviews them prior to submission to the SER. The GC represents by this review that he determined and verified all field measurements and field construction conditions. For more details see Standard Construction Document – CCDC 2 – 1994, GC 3.11 SHOP DRAWINGS, sentence 3.11.3.

5.2.2 Residential. Truss manufacturers submit the truss design drawings to the GC, who reviews them. The GC represents by this review that he determined and verified all field measurements and field construction conditions.

5.2.3 Farm. Truss manufacturers submit the truss design drawings to the GC, who reviews them prior to submission to the BD. The GC represents by this review that he determined and verified all field measurements and field construction conditions.

5.3 Production

Truss identification marking

5.3.1 Every truss shall be clearly identified by markings corresponding with those on the truss placement drawing.

5.3.2 Truss marking.

5.3.2.1 Bottom chord bearing parallel chord trusses shall be clearly marked in a manner which will avoid inverted installation.

5.3.2.2 Trusses having bearing locations other than at the end or heel locations or are not symmetrical shall have bearing points clearly marked.

5.3.2.3 Trusses having point loads, other than symmetrical, shall have point loads location clearly marked.


5.4 Truss Design Engineer

5.4.1 The truss design engineer is responsible only for the structural adequacy of the individual components based on the supplied design criteria and specified loading. 


5.5 Documentation Package

5.5.1 The truss manufacturer shall deliver the documentation package on the job site prior to installation. Unless otherwise specified in tender documents, the documentation package includes:
  • Truss design drawings for all trusses included in shipment
  • Truss placement drawing
  • Erection procedures pamphlet
  • List of materials
  • Special instructions as needed (Girder laminating, lateral braces, “T” braces, etc.)

5.6 Shipping

5.6.1 Truss manufacturer is responsible that trusses are in good condition when loaded and properly fastened to prevent damage. 

5.6.2 When delivery is not part of truss manufacturer’s contract, the truck driver is responsible for fastening the load to prevent damage.

5.6.3 When delivery is not part of his contract the truss manufacturer is not responsible for any damage incurred after the load leaves his compound.

6. INSTALLATION PROCESS

6.1.1 It is the responsibility of the installer to report any damage to trusses immediately to the truss manufacturer. The installer is not allowed to repair trusses without instructions from the TDE.

6.1.2 The TDE may provide the installer with truss repair instructions for a fee. 

7. INSPECTIONS

7.1 Structural Engineer of Record or Building Designer

7.1.1 BD or his SER or a suitably qualified person working under their direction, examines the completed construction of the wood truss system to confirm that it has been constructed in accordance with the intent of the drawings and specifications. 

7.1.2 TDE shall assist the SER or BD by providing complete documentation to make the inspection possible.

7.2 Safety Code Officer

7.2.1 Truss manufacturers, members of the AWTFA shall assist Safety code officers who do site inspections by providing complete documentation to make the inspections possible.

7.2.2 AWTFA members encourage Safety Code Officers to attend courses to improve their knowledge of proper truss installation.

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