05450-Pre Engineered Metal Trusses

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SECTION 05450 PRE-ENGINEERED LIGHT GAGE STEEL TRUSSES

PART 1 - GENERAL

1.1 REFERENCES

Comply with, but not limited to the following documents. All referenced standards refer to the edition in force at the

time final plans and specifications are issued.

A. AISI American Iron and Steel Institute; Specification for the Design of Cold-Formed Steel Structural

Members

B. AISI American Iron and Steel Institute; Design Guide for Cold-Formed Steel Trusses

C. ASTM Standards

D. AWS D1.0 Code for Welding in Building Construction.

E. FBC, Florida Building Code

1.2 SYSTEM REQUIREMENTS

A. Design Requirements: Provide Pre-engineered light gauge steel truss system which is designed and fabricated

to comply with the requirements of the Contract Documents and which strictly conforms to material,

manufacturing, and erection requirements of the Truss Manufacturer, and Truss Specialty Engineer.

B. Performance Requirements: Truss system, with framing components and accessories, shall provide a complete

horizontal framing system, ready for deck installation, meeting the specified Design Requirements. Shim as

required to provide uniform and smooth transitions between adjacent trusses and between trusses and walls

that extend to the roof deck.

C. Component Requirements: Truss chord and web components shall have rolled or closed edges to minimize the

danger of cutting during handling. Chord and web components without rolled edges shall not be accepted.

D. Truss Configuration: Arrangement of web member shall be at the discretion of the design engineer.

Coordinate web spacing as required for mechanical duct requirements. Joint centerlines of members shall

intersect at a common work point or the Specialty Engineer shall consider imposed loads due to eccentricity in

the truss design.

1.3 QUALIFICATIONS

A. The light gauge steel subcontractor shall have experience in fabrication and erection of light gauge steel truss

and framing systems of scope and design similar to the required work.

B. Trusses shall be designed, fabricated, and erected by a firm which has a record including a minimum of five

years of successfully designing, fabricating and erecting trussed assemblies similar to scope required and

which practices a quality control program which includes inspection by an independent inspection and testing

agency acceptable to architect and authorities having jurisdiction.

1.4 SUBMITTALS

A. Product Data:

Community Maritime Park Pre-Engineered Light Gage Trusses

Pensacola, Florida

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1. Submit fabricators technical data covering materials, shapes, hardware, fabrication process, handling

and erection.

2. Submit certificate, signed by an officer or subcontractor or fabricating firm, indicating that trusses to

be supplied for project comply with indicated requirements.

B. Shop Drawings:

1. Submit shop drawings showing shapes and dimensions of members to be used including pitch, span,camber configuration and spacing for each type or configuration of truss required.

2. Show all bearing and anchorage details.

3. Specify and detail all supplemental strapping, bracing clips and other accessories required for proper

installation.

4. Shop drawings shall include all placement sequences and instructions.

5. Submit design analysis and test reports indicating loading, section properties, allowable stress, stress

diagrams and calculations, and similar information needed for analysis and to insure trusses comply

with requirements.

6. All drawings and calculations shall bear the name and seal of a Structural Engineer licensed to practice

in the state where the trusses are to be erected.

C. Quality Assurance

1. Truss Manufacturers Instructions: Printed installation instructions for each item of cold-formed metal

framing and each accessory specified in this section.

2. Design Data: Results of design analysis, bearing the seal and signature of a professional engineer

registered in the State in which the project is located.

1.5 QUALITY ASSURANCE

A. Confer at job site prior to scheduled beginning of construction activities of this section to review requirements

of this section.

B. Review potential interface conflicts:

1. Coordinate layout and support provisions.

2. Coordinate mechanical and electrical work.

PART 2 - PRODUCTS

2.1 COMPONENTS

A. Load bearing members: Mechanical properties of components shall be determined by testing conforming to

ASTM A370- Standard Test Methods and Definitions for Mechanical Testing of Steel Products. Members

shall be cold-formed to indicated sizes, profiles, and thickness of steel conforming to ASTM A653, minimum

G60 coating, and ASTM A500 as follows:

1. Chord materials:

-Minimum yield strength 55,000 ksi.

-20 gage minimum

-4 minimum depth

-Provide members of gage and shape required for unbraced lengths

2. Web materials:

-Minimum yield strength 45,000 ksi

-22 gage minimum

-4 minimum depth

-Provide members of gage and shape required for unbraced lengths


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3.1 INSTALLATION

A. Field Fastening: Use correct fastening of trusses to structure as specified by the Specialty Engineer.

B. Metal Trusses:

1. Install trusses in accordance with the Truss Manufacturers instructions and recommendations. Place

components at spacings required. Install temporary bracing as required. Temporary bracing shallsupport trusses straight and plumb and in safe condition until decking and permanent truss bracing is

securely installed. All contractors shall use proper construction procedures to insure adequate

distribution of construction loads so as not to exceed design loads.

2. Install required permanent bracing as indicated on the drawings in addition to the permanent bracing

or bridging required by the Truss Manufacturer. All bracing and or bridging shall be installed prior to

application of loads.

3. Field cutting or alterations of the trusses or bracing is prohibited.

4. Damaged trusses shall be repaired of replaced as directed by the Truss Specialty Engineer.

5. All trusses shall be installed by approved methods using equipment of adequate capacity to safely

perform the work.

6. Provide web stiffeners and reinforcement at reaction points where required by the Truss Specialty

Engineer.

C. Site Tolerances for Truss Bearings:

1. Variation from level or specified plane: maximum 1/8 inch in 10 ft.

2. Variation from specified position: maximum 1/4 inch.

3. The contractor shall be responsible for checking the dimensions and spacings indicated on the

drawings.

3.3 FIELD QUALITY CONTROL

A. General: Engage a qualified independent testing agency to perform field quality control testing as indicated

below:

1. Verify locations, sizes, and spacing of trusses.

2. Inspection of truss to truss and truss to structure connections.

B. Provide access for independent testing agency so that inspections can be accomplished safely.

END OF SECTION 05450


Pensacola, Florida

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