Multi-Institutional Academic Health Science & Research Center Evansville, IN

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1 SECTION ALTERNATING TREAD STEEL STAIRS PART 1 - GENERAL 1.1 RELATED DOCUMENTS A. Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 1 Specification Sections, apply to this Section. 1.2 SUMMARY A. This Section includes alternating tread steel stairs. B. Related Sections include the following: 1. Division 5 Section "Metal Stairs" for conventional metal stairs. 2. Division 5 Section "Metal Stairs for railings adjacent to alternating tread steel stairs. 1.3 PERFORMANCE REQUIREMENTS A. General Code Compliance: Provide alternating tread steel stairs that comply with the requirements of the Connecticut Building Code based on providing a means of egress including the following: 1. Stair Treads: Minimum projected tread of 8 1/2 inches with a minimum projected tread depth of 10 1/2 inches. 2. Stair Risers: Maximum rise of 8 inches. B. Structural Performance: Provide alternating tread steel stairs capable of withstanding the following structural loads without exceeding the allowable design working stress of the materials involved, including anchors and connections. Apply each load to produce the maximum stress in each component of metal stairs. 1. Uniform Load: 100 lbf/sq. ft. (4.79 kn/sq. m). 2. Concentrated Load: 300 lbf (1.33 kn) applied on an area of 4 sq. in. (2580 sq. mm). 3. Uniform and concentrated loads need not be assumed to act concurrently. 4. Stair Framing: Capable of withstanding stresses resulting from railing loads in addition to loads specified above. 5. Limit deflection of treads, platforms, and framing members to L/360 or 1/4 inch (6.4 mm), whichever is less. 6. Alternating Tread Stair Treads: shall be capable of withstanding a single concentrated 1000 pound load without permanent deformation. 7. Alternating Tread Stair Stringers: shall be capable of withstanding a single concentrated load of 1000 pounds at any point on the stair without permanent deformation. C. Structural Performance of Handrails: Provide handrails capable of withstanding the following structural loads without exceeding allowable design working stresses of materials for handrails, anchors, and connections: 1. Handrails and Top Rails of Guards: ALTERNATING TREAD STEEL STAIRS

2 a. Uniform load of 50 lbf/ft. (0.73 kn/m) applied in any direction. b. Concentrated load of 200 lbf (0.89 kn) applied in any direction. c. Uniform and concentrated loads need not be assumed to act concurrently. 1.4 SUBMITTALS A. Shop Drawings: Show fabrication and installation details for alternating tread steel stairs. Include plans, elevations, sections, and details of stairs and their connections. Show anchorage and accessory items. Provide templates for anchors and bolts specified for installation under other Sections. 1. For installed products indicated to comply with design loads, include structural analysis data signed and sealed by the qualified professional engineer licensed in the state of Indiana responsible for their preparation. B. Qualification Data: For firms and persons specified in "Quality Assurance" Article to demonstrate their capabilities and experience. Include lists of completed projects with project names and addresses, names and addresses of architects and owners, and other information specified. 1.5 QUALITY ASSURANCE A. Fabricator Qualifications: A firm experienced in producing metal stairs similar to those indicated for this Project and with a record of successful in-service performance, as well as sufficient production capacity to produce required units. B. Welding: Qualify procedures and personnel according to AWS D1.1, "Structural Welding Code-- Steel," and AWS D1.3, "Structural Welding Code--Sheet Steel." 1.6 COORDINATION A. Coordinate installation of anchorages for alternating tread steel stairs. Furnish setting drawings, templates, and directions for installing anchorages, including sleeves, concrete inserts, anchor bolts, and items with integral anchors, that are to be embedded in concrete or masonry. Deliver such items to Project site in time for installation. PART 2 - PRODUCTS 2.1 MANUFACTURER A. Product: Subject to compliance with requirements, provide alternating steel tread stairs as manufactured by Lapeyre Stair, Inc. 2.2 MATERIALS A. Carbon Steel 1. Treads: 13 Gauge; Minimum 36 ksi yield stress; AISI 1010/15 HRPO or ASTM A1011 structural steel (SS) type grade 36 (or higher). ALTERNATING TREAD STEEL STAIRS

3 2. Landing & Foot Stampings: 11 Gauge; Minimum 36 ksi yield stress; AISI 1010/15 or ASTM A1011 structural steel (SS) type grade 36 (or higher). 3. Top Landing Support Clips: Formed L2 x 2 x ¼ x 4 lg. with 5/8 Φ round holes and 5/8 x 1 slot holes, ASTM A1011 structural steel (SS) Type, grade 36 (or higher) 4. Stringers: a. 3" x 1 3/4" x 11 Gauge U section; minimum 36 ksi yield stress AISI 1010/15 or ASTM A1011 structural steel (SS) Type, grade 36 or higher for 56 degree stairs over 10 vertical feet and for 68 degree stairs over 12 vertical feet. 5. Handrails: 1-1/2 inches OD by inch 1010/15 CS per ASTM A569 cold drawn, fully annealed tube per ASTM Safety Gate: 1-1/4 square by 11 gauge 1010/15 per ASTM 569 B. Miscellaneous Material: 1. Rubber Spine: Hollow neoprene 2. Rubber Foot Divider: Solid neoprene 2.3 FINISHES A. Comply with NAAMM's "Metal Finishes Manual for Architectural and Metal Products" for recommendations for applying and designating finishes. B. Galvanizing: Hot-dip galvanize items as indicated to comply with ASTM A 153/A 153M for steel and iron hardware and with ASTM A 123/A 123M for other steel and iron products 2.4 FABRICATION, GENERAL A. Provide complete stair assemblies including all components necessary to support and anchor stairs on supporting structure. B. Fabricate alternating tread steel stairs to conform with performance and construction requirements, and in accordance with approved shop drawings. Fabricate and shop assemble to greatest extent possible. C. Weld connections to comply with the following: 1. Carbon Steel: Gas metal arc welded with treads spot welded to stringers and bolt-on handrails with included bolts using the specified materials. 2.5 ALTERNATING TREAD STEEL STAIRS A. Dimensional Requirements: Fabricate stairs to comply with the following: 1. Stair Angle: 56 degrees from horizontal as indicated on the Drawings. 2. Vertical Drop: The change in elevation, as shown on the Drawings, between the roof edge where the top landing will be attached and the drive surface where the base of the stair will be secured. ALTERNATING TREAD STEEL STAIRS

4 B. Landings, Treads, and Mounting Base: Provide components stamped and formed from single piece material. Stock shapes, hand forming, or welded remnants shall not be permitted. All stamped parts shall have integrally formed rigidizing bends and shall be spot welded to stringers of like material. C. Welds: Provide minimum of 8 welds per tread, and 12 welds each on the landing and mounting base. Each weld shall be quality controlled and be capable of withstanding a minimum of 2800 lbs. in shear. D. Pedestrian Surfaces: All surfaces shall be punched through with upset non-skid openings. E. Riser Spacing: Risers shall be equally spaced to within 3/16 inch for adjacent risers and to within 3/8 inch for any two non-adjacent risers on a stair. F. Handrails: Provide handrails contoured for body guidance and underarm support and shall be attached to the outside stringers and landings by bolting. G. Safety Gate: Provide security gate at bottom of stair to prevent unauthorized access. H. Landing Reinforcement: Provide reinforcement consisting of 1/4 inch steel angle notched and punched and factory welded to the landing at the points of a handrail attachment. I. Rubber Foot Divider: Provide divider affixed to the central portion of the landing. A rubber bumper strip shall be attached or shall be provided for field attaching to the central stringer. PART 3 - EXECUTION 3.1 PREPARATION A. Coordination: Coordinate start and installation of steel alternating treads with all other related and adjacent work. Installation shall not start until the construction has progressed to the point that weather conditions and remaining construction operations will not damage stair installation. B. Verification: Verify that dimensions and angle are correct and that substrate is in proper condition for stair installation. Do not proceed to install until all necessary corrections have been made. 3.2 INSTALLATION A. If bumper has not been installed at the factory, install the bumper in accordance with the manufacturer's instructions using glue supplied with the stair. B. Prepare mounting holes. C. Position stair with top tread at same elevation as upper finished floor or roof surface. D. Secure stair with not less than 2 bolts or studs at top and with not less than 2 at bottom of stair. E. Touch up with matching paint any chipped or abraded damage to factory finish. 3.3 CLEANING ALTERNATING TREAD STEEL STAIRS

5 A. Leave work area clean and free of debris. END OF SECTION ALTERNATING TREAD STEEL STAIRS