SECTION METAL STAIRS

Transcription

1 SECTION METAL STAIRS PART 1 GENERAL 1.1 SUMMARY A. Section includes steel stair frame of structural sections, with closed risers; pan to receive concrete fill stair treads and landings; integral balusters and handrailing. B. Related Sections: 1. Section Metal Railings: Handrails and balusters other than specified in this section. 2. Section Rough Carpentry Wood Blocking 3. Section Painting and Coating: Paint finish. 1.2 REFERENCES A. American National Standards Institute: 1. ANSI A Accessible and Usable Buildings and Facilities. B. ASTM International: 1. ASTM A36/A36M - Standard Specification for Carbon Structural Steel. 2. ASTM A53/A53M - Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc- Coated, Welded and Seamless. 3. ASTM A123/A123M - Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products. 4. ASTM A153/A153M - Standard Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware. 5. ASTM A307 - Standard Specification for Carbon Steel Bolts and Studs, PSI Tensile Strength. 6. ASTM A325 - Standard Specification for Structural Bolts, Steel, Heat Treated, 120/105 ksi Minimum Tensile Strength. 7. ASTM A500/A500M - Standard Specification for Cold-Formed Welded and Seamless Carbon Steel Structural Tubing in Rounds and Shapes. 8. ASTM A501 - Standard Specification for Hot-Formed Welded and Seamless Carbon Steel Structural Tubing. 9. ASTM A563 - Standard Specification for Carbon and Alloy Steel Nuts. 10. ASTM A572/A572M - Standard Specification for High-Strength Low-Alloy Columbium- Vanadium Structural Steel. 11. ASTM F844 - Standard Specification for Washers, Steel, Plain (Flat),Unhardened for General Use 12. ASTM E935 - Standard Test Methods for Performance of Permanent Metal Railing Systems and Rails for Buildings. 13. ASTM E985 - Standard Specification for Permanent Metal Railing Systems and Rails for Buildings. Project Number METAL STAIRS

2 C. American Welding Society: 1. AWS A2.4 - Standard Symbols for Welding, Brazing, and Nondestructive Examination. 2. AWS D1.1 - Structural Welding Code - Steel. D. National Association of Architectural Metal Manufacturers: 1. NAAMM AMP Metal Stairs Manual. E. National Ornamental & Miscellaneous Metals Association: 1. NOMMA Guideline 1 - Joint Finishes. F. SSPC: The Society for Protective Coatings: 1. SSPC - Steel Structures Painting Manual. 1.3 DESIGN REQUIREMENTS A. Fabricate stair assembly to support uniform live load of[100 lb/sq ft and concentrated load of 300 lb/sq ft with deflection of stringer or landing framing not to exceed 1/180 of span. B. Railing assembly, wall rails, and attachments to resist lateral force of 75lbs at any point without damage or permanent set. Test in accordance with ASTM E SUBMITTALS A. Section Submittal Procedures: Submittal requirements. B. Shop Drawings: Indicate profiles, sizes, dimensions, connection attachments, reinforcing, anchorage, size and type of fasteners, and accessories. C. Shop Drawings: Indicate welded connections using standard AWS A2.4 welding symbols. Indicate net weld lengths. D. Design Data: Submit design calculations. 1.5 QUALITY ASSURANCE A. Perform Work in accordance with ASTM E985 - Permanent Metal Railing Systems and Rails for Buildings. B. Finish joints in accordance with NOMMA Guideline QUALIFICATIONS A. Prepare Shop Drawings under direct supervision of Professional Engineer experienced in design of this Work and licensed at Project location. 1.7 PRE-INSTALLATION MEETINGS A. Section Administrative Requirements: Pre-installation meeting. Project Number METAL STAIRS

3 1.8 FIELD MEASUREMENTS A. Verify field measurements prior to fabrication. PART 2 PRODUCTS 2.1 METAL STAIRS A. Manufacturers: 1. American Stair Corp. 2. The Sharon Companies Ltd. 3. Substitutions: Section Product Requirements 2.2 COMPONENTS A. Structural W-Shapes: ASTM A992/A992M. B. Structural T-Shapes: Cut from structural W-shapes. C. Channels and Angles: ASTM A36/A36M. D. Round Hollow Structural Sections: ASTM A500/A500M, Grade B. E. Square and Rectangular Hollow Structural Sections: ASTM A500/A500M, Grade B.] F. Structural Pipe: ASTM A53/A53M, Grade B. G. Tubing: ASTM A513, Type 5, minimum 50 ksi yield strength. H. Structural Plates: ASTM A36/A36M. I. Floor Plates: ASTM A786/A786M; J. Tread and Landing Concrete Reinforcement: Bar type K. Bolts: ASTM A307; Grade A.; Type Finish: Hot dipped galvanized. L. Nuts: ASTM A563 heavy hex type. 1. Finish: Hot dipped galvanized. M. Washers: 1. For ASTM A307 Bolts: ASTM F844. a. Finish: Hot dipped galvanized. 2. For [ASTM A325 Bolts: ASTM F436; Type 1. a. Finish: Hot dipped galvanized. Project Number METAL STAIRS

4 N. Exposed Mechanical Fastenings: Flush countersunk screws or bolts; consistent with design of stair structure. O. Welding Materials: AWS D1.1; type required for materials being welded. P. Shop Primer: SSPC Paint 15, Type 1, red oxide. Q. Touch-Up Primer: Match shop primer. R. Stair Treads: Concrete in metal pan; minimum two inches deep; smooth surface; with non-slip edge as specified. S. Concrete for Treads and Landings: Portland cement Type I, 3000 psi 28 day strength, 2 to 3 inch slump. 2.3 STEEL RAILING SYSTEM COMPONENTS A. Reference Drawings for further system description and dimensions. B. Hollow Structural Sections: ASTM A500/A500M, Grade B. C. Top Rails and Intermediate Post: 2 inch x 1/4 inch flat steel bar; welded joints. D. Corner Posts: 2 x 2 inch square steel tubing; welded joints. E. Balusters: 1/2 x 1/4 inch rectangular steel sections, welded to post. F. Fittings: Elbows, T-shapes, wall brackets, escutcheons; machined steel. G. Mounting: Steel brackets and flanges, prepare backing plate for mounting in metal stud wall construction. H. Exposed Fasteners: Flush countersunk screws or bolts; consistent with design of railing. I. Splice Connectors: Steel [concealed spigots] [welding collars] [threaded collars]. J. Shop Primer: SSPC Paint 15, Type 1, red oxide. K. Touch-Up Primer: Match shop primer. 2.4 FABRICATION A. Fit and shop assemble components in largest practical sections, for delivery to site. B. Fabricate components with joints tightly fitted and secured. C. Continuously seal joined pieces by intermittent welds and plastic filler. D. Grind exposed joints flush and smooth with adjacent finish surface. Make exposed joints butt tight, flush, and hairline. Ease exposed edges to small uniform radius. Project Number METAL STAIRS

5 E. Exposed Mechanical Fastenings: Flush countersunk screws or bolts; unobtrusively located; consistent with design of component, except where specifically noted otherwise. F. Supply components required for anchorage of fabrications. Fabricate anchors and related components of same material and finish as fabrication, except where specifically noted otherwise. G. Accurately form components required for anchorage of stairs, landings and railings to each other and to building structure. 2.5 FABRICATION - PAN STAIRS AND LANDINGS A. Fabricate stairs and landings with closed risers and treads of metal pan construction, ready to receive concrete. B. Form treads and risers with minimum 14 gage sheet steel stock. C. Secure reinforced tread pans to stringers with clip angles; welded in place. D. Form stringers with rolled steel channels, 12 inches deep. E. Form landings with minimum 14 gage sheet stock. Reinforce underside with angles or metal T's as required to attain design load requirements. 2.6 SHOP FINISHING A. Prepare surfaces to be primed in accordance with SSPC SP 2. B. Clean surfaces of rust, scale, grease, and foreign matter prior to finishing. C. Do not prime surfaces in direct contact with concrete or where field welding is required. D. Prime paint items with one coat. E. Galvanizing for Fasteners, Connectors, and Anchors: 1. Hot-Dipped Galvanizing: ASTM A153/A153M. 2. Mechanical Galvanizing: ASTM B695; Class 50 minimum. PART 3 EXECUTION 3.1 EXAMINATION A. Section Administrative Requirements: Coordination and project conditions. B. Verify field conditions are acceptable and are ready to receive work. C. Verify concealed blocking and reinforcement is installed and correctly located to receive wall mounted handrails. Project Number METAL STAIRS

6 3.2 PREPARATION A. Clean and strip primed steel items to bare metal where site welding is required. B. Supply items required to be [cast into concrete] [and] [or] [embedded in masonry] with setting templates. 3.3 INSTALLATION A. Install components plumb and level, accurately fitted, free from distortion or defects. B. Install anchors, plates angles hangers and struts required for connecting stairs to structure. C. Allow for erection loads. Install sufficient temporary bracing to maintain framing safe, plumb, and in alignment. D. Field weld components where indicated on drawings and shop drawings. Perform field welding in accordance with AWS D1.1. E. Field bolt and weld to match shop bolting and welding. Conceal bolts and screws whenever possible. Where not concealed, use flush countersunk fastenings. F. Mechanically fasten joints butted tight, flush, and hairline. Grind welds smooth and flush. G. Obtain approval of Architect/Engineer prior to site cutting or creating adjustments not scheduled. H. After erection, prime welds, abrasions, and surfaces not shop primed, except surfaces to be in contact with concrete. 3.4 ERECTION TOLERANCES A. Section Quality Requirements: Tolerances. B. Maximum Variation From Plumb: 1/4 inch per story, non-cumulative. C. Maximum Offset From Alignment: 1/4 inch. 3.5 FIELD QUALITY CONTROL A. Welding: Inspect welds in accordance with AWS D1.1. END OF SECTION Project Number METAL STAIRS

7 SECTION STAIR NOSINGS PART 1 GENERAL 1.1 SUMMARY A. Section includes single component stair nosing systems. 1.2 REFERENCES A. American National Standards Institute: 1. ANSI A Accessible and Usable Buildings and Facilities. B. ASTM International: 1. ASTM B Standard Specification for Aluminum and Aluminum-Alloy Extruded bars, Rods, Wire, Shapes and Tubes 1.3 DESIGN REQUIREMENTS A. Stair nosing assembly shall be cast in place with slip resistant surfaces. 1.4 SUBMITTALS A. Section Submittal Procedures: Submittal requirements. B. Submit manufacturer s specifications and technical data. C. Shop Drawings: Indicate profiles, sizes, connection attachments and accessories. 1.5 QUALITY ASSURANCE A. Manufacturer shall have a minimum of ten years experience in the fabrication of stair nosing systems. B. Installer shall have a minimum of three years of successful experience in the installation of similar nosing systems and be approved by manufacturer. PART 2 PRODUCTS 2.1 STAIR NOSING A. Manufacturers: 1. Balco Inc. 2. Babcock Davis 3. Substitutions: Section Product Requirements Project Number STAIR NOSINGS

8 2.2 COMPONENTS A. Stair Nosing System 1. Aluminum: ASTM B 221, alloy 6063-T5 extruded aluminum. 2. Depth: 3 3. Overhang: 1-1/2 B. Abrasive: Ribbed Bar Abrasive C. Fasteners: Cast Stair Nosing s with wing anchors. 2.3 FABRICATION A. Fabricate nosing assemblies as detailed. Provide anchors and accessories necessary for complete installation. PART 3 EXECUTION 3.1 EXAMINATION A. Section Administrative Requirements: Coordination and project conditions. B. Verify field conditions are acceptable and are ready to receive work. 3.2 INSTALLATION A. Install in accordance with all governing regulations and industry standards applicable to the work, and with manufacturers installation instructions. B. Work shall be aligned plumb, level, and where required, flush with adjacent surfaces and rigidly anchored to the substrate. 3.3 CLEANING A. Clean exposed surfaces as recommended by the manufacturer. 3.4 PROTECTION A. Protect finished work from damage by work of other trades during construction. B. Finished units shall be without damage or visible deterioration. END OF SECTION Project Number STAIR NOSINGS