MasterFormat: 95

Download this Pre-engineered Cold-formed Steel Trusses Specification for   WORD | WP | RTF | TEXT

Find over 500 more construction specifications | Arcat.com

	SECTION 05425
	PRE-ENGINEERED COLD-FORMED STEEL TRUSSES
	** NOTE TO SPECIFIER ** Aegis; factory-built light gage cold formed steel floor and roof trusses. . This section based on products made by authorized fabricators of Aegis Metal Framing LLC, a Dietrich/MiTek Joint Venture, which is located at: 14515 North Outer 40 Drive, Suite 110 Chesterfield, MO 63017 Te1: (866) 902-3447 Te1: (314) 851-2200 Fax: (314) 434-5234 www.aegismetalframing.com www.ultraspan.com Email: answers@aegismetalframing.com [ Click Here ] for additional information. . Total solutions for the Building Component Industry. Aegis is the world's leading supplier of state-of-the-art-engineered products and services for the building components industry. Nobody else can come close to our capabilities for fulfilling customer needs - locally, nationally and internationally. . Aegis provides materials, design and fabrication software, and engineering services to local and regional fabricators of Ultra-Span(r) and Posi-Strut(r) light gage steel floor and roof trusses. Visit www.aegismetalframing.com for the names and locations of fabricators in the vicinity of your project. .
	PART 1	GENERAL
	1.1	SECTION INCLUDES
		A.	Pre-engineered, factory-built light gage cold-formed steel framing elements.
	** NOTE TO SPECIFIER ** Delete items below not required for project.
			1.	Light gage cold-formed steel open web floor trusses.
			2.	Light gage cold-formed steel roof trusses.
			3.	Anchorage, bracing and bridging.
	1.2	RELATED SECTIONS
	** NOTE TO SPECIFIER ** Delete any sections below not relevant to this project; add others as required.
		A.	Section 05300 - Metal Decking
		B.	Section 05400 - Cold-Formed Steel Framing
		C.	Section 06100 - Rough Carpentry.
		D.	Section 07210 - Building Insulation.
		E.	Section 07410 - Metal Wall and Roof Panels.
		F.	Section 07630 - Sheet Metal Roofing Specialties.
	1.3	REFERENCES
	** NOTE TO SPECIFIER ** Delete references from the list below that are not actually required by the text of the edited section.
		A.	AISI - Specification for Design of Cold-Formed Steel Structural Members, 2001.
		B.	AISI - Standard for Cold-Formed Steel Framing, Truss Design, 2001.
		C.	ASTM - A 653/A 653M Standard Specification for Sheet Steel, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot Dip Process.
		D.	ASTM - A 780 Standard Practice for Repair of Damaged and Uncoated Areas of Hot Dip Galvanized Coatings.
		E.	AWS - D 1.1 Structural Welding Code - Steel.
		F.	AWS - D 1.3 Structural Welding Code - Sheet Steel.
		G.	AWS B2.1 - Specification for Welding Procedure and Performance Qualification.
		H.	LGSEA - Light Gauge Steel Engineers Association "Field Installation Guide".
	1.4	DESIGN / PERFORMANCE REQUIREMENTS
		A.	AISI Specifications: Calculate structural characteristics of cold-formed steel truss members according to AISI Specification for Design of Cold-Formed Steel Structural Members.
		B.	Structural Performance: Design, engineer, fabricate, and erect cold-form steel trusses to withstand specified design loads within limits and under conditions required.
			1.	Design Loads: As specified.
			2.	Deflections: Live load deflection meeting the following (unless otherwise specified):
	** NOTE TO SPECIFIER ** Delete paragraphs below that do not apply.
				a.	Floor Trusses: Vertical deflection less than or equal to 1/480 of span.
				b.	Roof trusses: Vertical deflection less than or equal to 1/240 of span.
			3.	Design framing systems to provide for movement of framing members without damage or overstressing, sheathing failure, connection failure, undue strain on fasteners and anchors, or other detrimental effects when subject to maximum ambient temperature change (range) of 120 degrees F (67degrees C).
	1.5	SUBMITTALS
		A.	Submit under provisions of Section 01300.
		B.	[ Product Data ]: Manufacturer's data sheets on each product to be used, including:
			1.	Preparation instructions and recommendations.
			2.	Storage and handling requirements and recommendations.
			3.	Installation methods.
		C.	Shop Drawings:
			1.	Submit shop drawings showing each member type, location, spacing, size and gage, methods of attachment to supporting members and all necessary erection details. Indicate supplemental bracing, strapping, splices, bridging, accessories and details required for proper installation.
			2.	Submit detailed floor truss and roof truss layouts.
			3.	Submit truss drawings, sealed and signed by a qualified registered Professional Engineer, verifying truss ability to meet local code and design requirements. Include the following:
				a.	Description of design criteria.
				b.	Engineering analysis depicting member stresses and truss deflection.
				c.	Truss member sizes and gages and connections at truss joints.
				d.	Truss support reactions.
				e.	Top chord, bottom chord and web bracing requirements.
		D.	Manufacturer's Certificates: Certify products meet or exceed specified requirements.
	1.6	QUALITY ASSURANCE
		A.	Fabricator Qualifications: Cold-formed steel truss fabricator with experience designing and fabricating cold-formed steel truss systems equal in material, design and extent to the systems required for this project and approved by truss component manufacturer.
		B.	Installer Qualifications: Experienced installer with experience installing cold-formed steel truss systems equal in material, design and extent to the systems required for this project and approved by truss system fabricator.
	** NOTE TO SPECIFIER ** Include a mock-up if the project size and/or quality warrant taking such a precaution. The following is one example of how a mock-up on a large project might be specified. When deciding on the extent of the mock-up, consider all the major different types of work on the project.
		C.	Welding Standards:
			1.	Comply with applicable provisions of AWS D 1.1 and AWS D 1.3.
			2.	Qualify welding processes and welding operators in accordance with AWS B2.1.
	1.7	DELIVERY, STORAGE, AND HANDLING
		A.	Deliver materials in manufacturer's unopened containers or bundles, fully identified by name, brand, type and grade. Exercise care to avoid damage during unloading, storing and erection.
		B.	Store trusses on blocking, pallets platforms or other supports off the ground and in an upright position sufficiently braced to avoid damage from excessive bending.
		C.	Protect trusses and accessories from corrosion, deformation, damage and deterioration when stored at job site. Keep trusses free of dirt and other foreign matter.
	1.8	PROJECT CONDITIONS
		A.	Maintain environmental conditions (temperature, humidity, and ventilation) within limits recommended by manufacturer for optimum results. Do not install products under environmental conditions outside manufacturer's absolute limits.
		B.	During construction, adequately distribute all loads applied to trusses so as not to exceed the carrying capacity of any one joist, truss or other component.
	PART 2	PRODUCTS
	2.1	MANUFACTURERS
		A.	Acceptable Manufacturer Aegis Metal Framing LLC; 14515 North Outer 40 Drive, Suite 110, Chesterfield, MO 63017. ASD. Tel: (866) 902-3447 or (314) 851-2200. Fax: (314) 434-5234. www.aegismetalframing.com. Email: answers@aegismetalframing.com.
		B.	Substitutions: Not permitted.
		C.	Requests for substitutions will be considered in accordance with provisions of Section 01600.
	2.2	COMPONENTS
	** NOTE TO SPECIFIER **The following paragraphs include light gage roof trusses and light gage floor trusses. Edit the following paragraphs if required to include only the components required.
		A.	System components: Aegis Metal Framing, LLC ULTRA-SPAN and POSI-STRUT light gauge steel roof truss and floor truss components.
		B.	Provide manufacturer’s standard steel truss members, bracing, bridging, blocking, reinforcements, fasteners and accessories with each type of steel framing required, as recommended by the manufacturer for the applications indicated and as needed to provide a complete cold-formed steel truss roof or floor assembly.
	2.3	MATERIALS
		A.	Materials:
			1.	For all chord and web members: Fabricate components of structural quality steel sheet per ASTM A653 with a minimum yield strength of 50,000 psi.
			2.	Bracing, bridging and blocking members: Fabricate components of commercial quality steel sheet per ASTM A653 with a minimum yield strength of 33,000 psi.
		B.	Ultra-Span steel truss components: Provide sizes, shapes and gauges indicated.
			1.	Design Uncoated-Steel Thickness: 0.0350 inch (0.89 mm) (nominal 20 gage).
			2.	Design Uncoated-Steel Thickness: 0.0460 inch (1.17 mm) (nominal 18 gage).
			3.	Design Uncoated-Steel Thickness: 0.0570 inch (1.45 mm) (nominal 16 gage).
			4.	Design Uncoated-Steel Thickness: 0.0730 inch (1.85 mm) (nominal 14 gage).
			5.	Design Uncoated-Steel Thickness: 0.0970 inch (2.46 mm) (nominal 12 gage).
		C.	Finish: Provide components with protective zinc coating complying with ASTM A653, minimum G60 coating.
		D.	Fastenings:
			1.	Manufacturer recommended self-drilling screws with corrosion-resistant plated finish. Fasteners shall be of sufficient size and number to ensure the strength of the connection.
			2.	Welding: Comply with AWS D1.1 when applicable and AWS D1.3 for welding base metals less than 1/8 inch (3 mm) thick.
			3.	Other fasteners as accepted by truss fabricator’s engineer.
	2.4	FABRICATION
		A.	Factory fabricate cold-formed steel trusses plumb, square, true to line, and with connections securely fastened, according to manufacturer's recommendations and the requirements of this Section.
			1.	Fabricate truss assemblies in jig templates.
			2.	Cut truss members by sawing or shearing or plasma cutting.
			3.	Fasten cold-formed steel truss members by screw fastening, or other methods as standard with fabricator.
			4.	Locate mechanical fasteners and install according to cold-formed steel truss component manufacturer's instructions with screw penetrating joined members by not less than three exposed screw threads.
		B.	Care shall be taken during handling, delivery and erection. Brace, block, or reinforce truss as necessary to minimize member and connection stresses. Handle and erect in accordance with the LGSEA "Field Installation Guide".
		C.	Fabrication Tolerances: Fabricate trusses to a maximum allowable tolerance variation from plumb, level, and true to line of 1/8 inch in 10 feet (1:960) and as follows:
			1.	Spacing: Space individual trusses no more than plus or minus 1/8 inch (3 mm) from plan location. Cumulative error shall not exceed minimum fastening requirements of sheathing or other finishing materials.
			2.	Squareness: Fabricate each cold-formed steel truss to a maximum out-of-square tolerance of 1/8 inch (3 mm).
	PART 3	EXECUTION
	3.1	EXAMINATION
		A.	Examine structure, substrates and installation conditions. Do not proceed with cold-formed steel truss installation until unsatisfactory conditions have been corrected.
		B.	If substrate preparation is the responsibility of another installer, notify Architect of unsatisfactory preparation before proceeding.
		C.	Installation constitutes acceptance of existing conditions and responsibility for satisfactory performance.
	3.2	INSTALLATION - GENERAL
		A.	Erection of trusses, including proper handling, safety precautions, installation bracing and other safeguards or procedures is the responsibility of the Contractor and Contractor’s installer. Erect in accordance with the LGSEA “Field Installation Guide”.
		B.	Exercise care and provide installation bracing required to prevent toppling of trusses during erection. Provide Ultra-Span Stabilizer from Aegis Metal Framing for lateral bracing.
		C.	Erect trusses with plane of truss webs vertical and parallel to each other, accurately located at design spacing indicated.
		D.	Provide proper lifting equipment, including spreader bar, suited to sizes and types of trusses required, applied at lift points recommended by truss fabricator. Exercise care to avoid damage to truss members during erection and to keep horizontal bending of the trusses to a minimum.
		E.	Provide framing anchors as indicated or accepted on the engineering design drawing or erection drawings. Anchor trusses securely at bearing points.
		F.	Install trusses plumb, square, true to line, and with connections securely fastened, according to manufacturer's recommendations.
			1.	Do not cut truss members without prior approval of manufacturer's truss engineer.
			2.	Fasten cold-formed steel trusses by screw fastening, welding or other methods, as standard with fabricator.
				a.	Comply with AWS requirements and procedures for welding, appearance and quality of welds, and methods used in correcting welding work.
				b.	Locate mechanical fasteners and install according to cold-formed truss manufacturer's instructions with screw penetrating joined members by not less than three exposed screw threads.
			3.	Install trusses in one-piece lengths, unless splice connections are indicated.
			4.	Provide installation bracing and leave in place until trusses are permanently stabilized.
		G.	Erection Tolerances: Install trusses to a maximum allowable tolerance variation from plumb, level, and true to line of 1/8 inch in 10 feet (1:960) and as follows:
			1.	Space individual trusses no more than plus or minus 1/8 inch (3 mm) from plan location. Cumulative error shall not exceed minimum fastening requirements of sheathing or other finishing materials.
			2.	Limit out-of-plane bow and plumb in accordance with the LGSEA "Field Installation Guide".
	** NOTE TO SPECIFIER **The following paragraphs include light gage roof trusses and light gage floor trusses. Edit the following paragraphs if required to include only the components required.
	3.3	ROOF TRUSS INSTALLATION
		A.	Install trusses in accordance with approved shop drawings.
		B.	Space trusses per sealed truss drawings.
		C.	Do not alter, cut, or remove truss members or connections of truss members.
		D.	Erect trusses with plane of truss webs plumb and parallel to each other, align, and accurately position at spacing indicated.
		E.	Erect trusses without damaging truss members or connections.
		F.	Anchor trusses securely at all points of support in accordance with approved shop drawings.
		G.	Install all continuous bridging and permanent truss bracing in accordance with approved shop drawings.
		H.	Perform all truss-to-truss connections in accordance with approved shop drawings.
	3.4	OPEN WEB FLOOR TRUSS INSTALLATION
		A.	Install perimeter joist track or belly band sized to match trusses. Align and securely anchor or fasten track to supporting structure at corners, ends, and spacing indicated or as recommended by the manufacturer.
		B.	Install trusses bearing on supporting framing, level, straight, and plumb.
			1.	Install trusses over supporting framing with a minimum end bearing of 1-1/2 inches (38 mm).
		C.	Space trusses in accordance with approved shop drawings drawings.
		D.	Frame openings with built-up joist headers consisting of joist and joist track, nesting joists, or another combination of connected joists where indicated.
		E.	Install bridging and permanent bracing in accordance with approved shop drawings.
		F.	Anchor trusses securely at all points of support in accordance with approved shop drawings.
	3.5	PROTECTION AND TOUCH-UP
		A.	Protect installed products until completion of project.
		B.	Touch-up, repair or replace damaged products before Substantial Completion.
		C.	Galvanizing Repairs: Prepare and repair damaged galvanized coatings on fabricated and installed cold-formed steel framing with galvanizing repair paint according to ASTM A780 and the manufacturer's instructions.
	END OF SECTION