A06_Prefabricated_Steel_Stair_System.docx

DIVISION 2 SECTION 05200

METALS PREFABRICATED STEEL STAIR SYSTEM

PART 1 – GENERAL

1.1 SUMMARY

· Work includes furnishing and installing a complete prefabricated steel stairway system supported on concrete foundation slabs, including stringers, treads, risers, landings, handrails, guardrails, anchors, and all required hardware.

1.2 RELATED SECTIONS

· Removals – Section 02000

1.3 REFERENCES

· ASTM A36 – Carbon Structural Steel

· ASTM A572 – High‑Strength Low‑Alloy Steel

· ASTM A123 – Hot‑Dip Galvanized Coatings

· ASTM F1554 – Anchor Bolts

· AWS D1.1 – Structural Welding Code

· IBC – International Building Code

· OSHA 1910/1926 – Stair and Railing Requirements

1.4 SUBMITTALS

· Shop Drawings from steel stair system manufacturer that show all system components, including stair and handrail geometry, stringer profiles, tread details, upper landing framing connection, anchor bolt layout, post supports, and interface with concrete slabs. Contractor to provide stair manufacturer stamped drawings and calculations by a registered Professional Engineer.

· Product Data: Steel grades, coatings, anchors, grout.

· Welding Certificates: AWS‑qualified welders.

· Installation Plan: Lifting, rigging, and sequencing.

· Quality Assurance: Inspection reports, mill certificates.

· The contractor shall submit manufacturers’ shop drawings and structural calculations for all components used in the construction of this Steel Stair System. The drawings and structural calculations shall be stamped by a Professional Engineer.

1.5 QUALITY ASSURANCE

· Fabricator shall have minimum 5 years’ documented experience producing prefabricated steel stairs.

· Welding shall comply with AWS D1.1.

· Field measurements must be verified prior to fabrication.

1.6 DELIVERY, STORAGE, AND HANDLING

· Protect stair components from deformation, corrosion, and coating damage.

· Store off the ground with adequate ventilation.

1.7 COORDINATION

· Coordinate anchor bolt placement with concrete contractor.

· Confirm slab elevations and bearing surfaces before installation.

PART 2 – PRODUCTS

2.1 MATERIALS

· Structural Steel: ASTM A36 or A572 Grade 50.

· Treads: 11 3/4" black bar grating treads with 3” toe kick and 1 3/16” bearing bar size spaced on 11/16” Centers with 1/2” maximum openings meeting ADA Guidelines.

· Stringers: Channel or plate stringers per design.

· Top Landing: Steel deck plate connected to existing wood framing.

· Handrails/Guardrails: Factory welded 1-1/2” x 11 Gauge square steel tubing meeting IBC and OSHA load requirements.

· Anchor Bolts: ASTM F1554, galvanized for exterior use if part of Manufacturers Standard Design.

· Grout: Non‑shrink, high‑strength grout, minimum 5,000 psi.

· Shims: Stainless or galvanized steel.

2.2 FABRICATION

· Prefabricate stair assemblies in shop to greatest extent possible.

· Weld connections unless bolted connections are shown.

· Provide smooth, uniform welds; grind exposed welds.

· Pre‑drill or punch holes for field bolting.

· Provide adjustable base plates for field leveling.

2.3 FINISHES

· Stair System: Hot‑dip galvanized per ASTM A123 and powder coated. Colors provided by Contractor for approval.

· Touch‑up coatings at damaged areas.

PART 3 – EXECUTION

3.1 EXAMINATION

· Verify concrete foundation slabs are level, cured, and free of defects.

· Confirm anchor bolt locations and elevations.

· Report discrepancies before installation.

3.2 INSTALLATION

· Set stair assemblies plumb, level, and aligned.

· Use steel shims to achieve required elevations; plastic shims are not permitted.

· Apply non‑shrink grout under base plates after final alignment.

· Bolt or weld connections as indicated on shop drawings.

· Install landings, treads, and railings securely and uniformly.

3.3 FIELD WELDING

· Perform welding per AWS D1.1.

· Protect adjacent surfaces from heat and spatter.

· Grind smooth and touch up coatings.

3.4 TOLERANCES

· Stair slope: ±1/4 inch over full run.

· Tread/riser uniformity: ±1/8 inch.

· Plumb of stringers: 1/8 inch in 10 feet.

· Base plate elevation: ±1/8 inch.

3.5 FIELD QUALITY CONTROL

· Inspect alignment, welds, bolt torque, and anchorage.

· Verify railing heights, spacing and structural loadings meet IBC/OSHA standards.

3.6 CLEANING AND PROTECTION

· Remove debris and metal filings.

· Protect stair surfaces until project completion.

3.7 FINAL ACCEPTANCE

· Stairway must be fully anchored, grouted, aligned, and finished.

· All safety rails installed and compliant with code.

05200-1