LONG BAY SYSTEM
BASIC MATERIAL SPECIFICATIONS
Issue Date: August 13, 2004
Section 1. Drawings and Certifications
1.1. Drawings: Manufacturer shall furnish complete erection drawings for the proper identification and assembly of all building components. These drawings will show anchor bolt settings, transverse cross-sections, sidewall, endwall and roof framing, flashing and sheeting, and accessory installation details.
1.2. Drawings: Manufacturer shall furnish complete erection drawings for the proper identification and assembly of all building components. These drawings will show anchor bolt settings, transverse cross-sections, sidewall, endwall and roof framing, flashing and sheeting, and accessory installation details.
1.3. Certifications: Standard drawings and design analysis shall bear the seal of a registered professional engineer upon request. Design analysis shall be on file and furnished by manufacturer upon request.
1.4. Bills of material shall be furnished and shall include item weights, if requested.
Section 2. Structural Steel Design
2.1. General
2.1.1. The building manufacturer shall use standards, specifications, recommendations, findings and/or interpretations of professionally recognized groups such as AISC, AISI, AAMA, AWS, ASTM, MBMA, Federal Specifications, and unpublished research by MBMA as the basis for establishing design, drafting, fabrication, and quality criteria, practices, and tolerances. For convenience, one or more sources may be referenced in a particular portion of these specifications. In all instances, however, the manufacturer's design, drafting, fabrication and quality criteria, practices, and tolerances shall govern, unless specifically countermanded by the contract documents. All materials shall be designed and fabricated by an AISC - MB category certified manufacturer.
2.1.2. Structural mill sections or welded up plate sections will generally be designed in accordance with the 9th edition of AISC's "Specification for the Design, Fabrication and Erection of Structural Steel for Buildings", ASD method.
2.1.3. Cold-Formed steel structural members will generally be designed in accordance with the latest edition of AISI's "Specifications for the Design of Cold-Formed Steel Structural Members".
2.2. Design Loads
2.2.1. Design loads shall be as specified and set forth in the contract, and shall be in accordance with the manufacturer's standard design practices. Design loads may include dead load, roof live loads, wind loads, seismic loads, collateral loads, auxiliary equipment loads, and/or other applied or specified loads.
2.2.2. Dead Load - the actual weight of the building system supported by a given member.
2.2.3. Roof Live Loads - loads produced by maintenance activities, rain, erection activities, and other movable or moving loads but not including wind, snow, seismic, crane, or dead loads.
2.2.4. Roof Snow Loads - gravity load induced by the weight of snow or ice on the roof, assumed to act on the horizontal projection of the roof.
2.2.5. Wind Loads - the loads on a structure induced by the forces of wind blowing from any horizontal direction.
2.2.6. Collateral Loads - the weight of any non-moving equipment or material, such as ceilings, electrical or mechanical equipment, sprinkler systems, plumbing, or ceilings.
2.2.7. Auxiliary Loads - dynamic loads induced by cranes, conveyors, or other material handling systems.
2.2.8. Seismic Loads - Loads acting in any direction on a structural system due to the action of an earthquake.
2.2.9. Floor Live Loads - loads induced on a floor system by occupants of a building and their furniture, equipment, etc.
Section 3. Primary Framing Steel
3.1. Steel for hot rolled shapes shall conform to the requirements of ASTM Specifications A-36 or A992, with minimum yield of 36 or 50 ksi.
3.2. Steel for built-up sections shall generally conform to the physical requirements of ASTM 1011, A529, A572 or A36 as applicable, with minimum yield of 42, 46, 50, or 55 ksi as indicated by the design requirements.
3.3. Steel for endwall "C" sections shall generally conform to the physical requirements of ASTM 1011 Grade 55, and have a minimum yield of 57 ksi.
Section 4. Secondary Framing Steel
4.1. Steel used to form purlins, girts, and eave struts shall meet the requirements of ASTM 1011 Grade 55. Minimum yield shall be 57 ksi.
Section 5. Structural Framing
5.1. All framing members shall be shop fabricated for field bolted assembly. The surfaces of the bolted connections shall be smooth and free from burrs or distortions.
5.2. All shop connections shall be in accordance with the manufacturer's standard design practices as specified in Paragraph 2.1.1. Certification of welder qualifications will be furnished when required and specified in advance.
5.3. All framing members, where necessary, shall carry an identifying mark.
Section 6. Primary Framing
6.1. Rigid Frame: All rigid frames shall be welded built-up "I" sections or hot-rolled sections. The columns and the rafters may be either uniform depth or tapered. Flanges shall be connected to webs by means of a continuous fillet weld on one side.
6.2. Endwall Frames: All endwall roof beams shall be mill-rolled sections, or built-up "I" sections depending on design requirements. All endwall columns shall be cold-formed "C" sections, mill-rolled sections, or built-up "I" sections depending on design requirements.
6.3. Plates, Stiffeners, etc.: All base plates, splice plates, cap plates, and stiffeners shall be factory welded into place on the structural members.
6.4. Bolt Holes, etc.: All base plates, splice and flanges shall be shop fabricated to include bolt connection holes. Webs shall be shop fabricated to include bracing holes.
6.5. Connections for secondary structural (purlins and girts) shall be ordinary bolted connections, which may include welded clips.
6.6. All welding inspection shall be by the manufacturer in accordance with the manufacturer’s AISC – MB category certification. Special inspection by the buyer or owner shall be done in the manufacturer’s facility and shall be noted on the contract documents.
Section 7. Secondary Framing
7.1. Purlins and Girts: Purlins shall be cold-formed open web Long Bay System assemblies (LBS) with stiffened chords. Purlins shall be simple span and connection bolts will install through the purlin seats. LBS assemblies shall be pre-punched to allow for attachment of frame flange brace angles, compression strut extensions and diagonal X-bridging at the centerline. All other bridging shall be furnished as light-gage cold-formed angles and shall be secured using self-drilling fasteners. All LBS sections shall be manufactured in a facility that holds a current, valid MB Quality Certificate issued by the American Institute of Steel Construction. The top and bottom chords of all LBS sections shall have a nominal width of 4” and shall be formed so that the top surface is continuous and flat to facilitate easy assembly of the chosen roof system. All elements of the LBS assembly shall be a minimum of 16 gauge. The finished assemblies shall be subject to periodic testing to loads equal to 110% of the design loads to ensure proper assembly processes. Girts shall be cold-formed "Z" sections with stiffened flanges. Flange stiffeners shall be sized to comply with the requirements of the latest edition of AISI. Girt flanges shall be unequal in width to allow for easier nesting during erection. They shall be prepunched at the factory to provide for field bolting to the rigid frames. Girts shall be simple or continuous span as required by design. Connection bolts will install through the webs, not the flanges.
7.2. Eave Struts: Eave Struts shall be unequal flange cold-formed "C" sections or LBS purlins.
7.3. Base Angle: A base member will be supplied by which the base of the wall covering may be attached to the perimeter of the slab. This member shall be secured to the concrete slab with ram-sets, expansion bolts, or equivalent anchors as shown on the drawings.
Section 8. Bracing
8.1. Diagonal Bracing: Wind bracing in the roof and/or walls need not be furnished where it can be shown that the diaphragm strength of the roof and/or wall covering is adequate to resist the applied wind or seismic forces. Diagonal bracing in the roof and sidewalls shall be used to resist longitudinal loads (wind, crane, etc.) in the structure if diaphragm action cannot be used. This bracing will be furnished to length and equipped with hillside washers and nuts at each end. It may consist of rods threaded each end or galvanized cable with suitable threaded end anchors. If load requirements so dictate, bracing may be of structural angle and/or pipe, bolted in place.
8.2. Special Bracing: When diagonal bracing is not permitted in the sidewall, a rigid frame type portal or fixed base columns will be used. Shear walls can also be used where adequate to resist the applied wind or seismic forces.
8.3. Flange Braces: The compression flange of all primary framing shall be braced laterally with angles connecting to the bottoms chords of purlins or to the webs of girts so that the flange compressive stress is within allowable limits for any combination of loading.
8.4. Bridging: The top chord of the LBS purlins shall be braced laterally with horizontal bridging if the roof system being used will not supply adequate lateral support to the top chord. The bottom chord will receive horizontal bridging to laterally brace the bottom chord. One row of bolted diagonal bridging will be required for all LBS purlins 40 ft. long and greater.
Section 9. Double-Lok® Machine seamed standing Seam Roof
9.1. Standing Seam Roof Panels shall be UL-90 rated, roll-formed, 24 or 22 gauge acrylic coated Galvalume® or pre-painted Galvalume®. Galvalume® sheet shall have 50% aluminum-zinc alloy–coating with a minimum yield of 50 ksi and conform to ASTM 792-99a. Pre-painted finish shall be a premium Fluoropon¨ coating produced with either Kynar 500® or Hylar 5000® resins and have a full 20 year warranty. Wherever used in this specification, acrylic-coated Galvalume® means Galvalume® with a light acrylic coating such as Galvalume Plus by Bethlehem, Acrylume by National or Galvalume Plus by U.S. Steel. This coating eliminates the need for roll-forming oil and reduces the incidence of field marking by handling or foot traffic.
9.2. Panels shall be 24" or 18” wide with 2 minor ribs in between seams. Panel seam shall be 3" high.
9.3. One side of the panel shall be female in configuration, which will have factory applied hot-melt mastic (see 9.9 Sealants And Closures) inside the female seam. The female side will snap over the male side. The male and female seams will be continuously locked together by an electrically powered mechanical seamer, forming a 360-degree Pittsburgh Seam.
9.4. The panels shall be factory notched at both ends so that field installation can commence or terminate from either end of the building. Panels cannot start at both ends of the building and work towards each other.
9.5. Maximum panel length shall be 45'-0" unless otherwise noted on the purchase order.
9.6. Endlaps
9.6.1. Endlaps shall have a 16 gauge backup plate. The panel shall have the eight endlap joint fasteners installed in six pre-punched holes in the flat and in the dimples in the trapezoidal legs.
9.6.2. Mastic (see Sealants And Closures) shall be applied between the panels and secured with 1/4" - #14 x 1 1/4 self-drilling fasteners through the panels, and backup plate to form a compression joint.
9.6.3. Endlaps and eaves shall be the only places in the roof system where through the roof fasteners can be used inside the building envelope.
9.7. Fasteners
9.7.1. Eave - 1/4" - #14 x 1 1/4" long life self-drilling with sealing washer.
9.7.2. Endlaps - 1/4" - #14 x 1 1/4” long life self-drilling with sealing washer.
9.7.3. Ridge - #14 x 7/8" Lap Tek long life self-drilling with sealing washer.
9.7.4. Clips/to purlin - 1/4" - #14 x 1 1/4" Tek 2 long life self-drilling with Hex Washer Head and 5/8" O.D. washer.
9.7.5. Clips/floating to bar joists - #12-24 x 1 1/4" Tek 4.5 self-drilling with Washer Head and 5/8" O.D. washer.
9.7.6. Long Life fasteners, where exposed, are standard when using an acrylic coated Galvalume® roof panel.
9.8. Clips
9.8.1. All clips shall have factory-applied mastic and be designed so that movement between the panel and the clip does not occur.
9.8.2. Low or High floating clips - shall be either 3 3/8" or 4 3/8" in height. Floating clips shall provide a minimum of 2" travel to allow for expansion and contraction.
9.9. Sealant And Closures
9.9.1. Factory applied sealant used in panel sidelaps shall be a hot melt, foamable mastic - Q41A.
9.9.2. Field applied sealant used at the endlaps, eave, ridge assembly, and gable flashings shall be 100% solids butyl-based elastomeric tape sealant, furnished in roll form or pre-cut to length. See manual for application.
9.9.3. Outside closures shall be manufactured from the same materials as the roof panels.
9.9.4. Inside closures shall be 18-gauge Galvalume ® or galvanized coated metal.
|
