Construction Process of Steel Structure Factory Buildings

I. Preliminary Procedures and Design Phase

Project initiation, land use approval, planning permits, environmental impact assessment, and construction permit processing

Site survey: Topographic mapping and geotechnical investigation; issuance of geotechnical reports and determination of soil bearing capacity

Design (Schematic + Construction Drawings)

Architectural drawings: Factory span, ceiling height, doors/windows, skylights, roof ventilators, and flooring

Steel structure construction drawings: Steel columns, beams, purlins, bracing, and crane beams (if overhead cranes are required)

Foundation, MEP (mechanical, electrical, plumbing), and fire safety drawings

Drawing review, budget preparation, and tendering to select the construction contractor and steel fabrication plant

II. Foundation Construction Phase (Civil Works First)

Site leveling, earthwork excavation, and backfilling with compaction

Pile foundation construction (for soft soil) / Excavation for isolated footings, formwork installation, and rebar tying

Installation of embedded anchor bolts (critical step; positioning accuracy directly affects steel structure installation)

Concrete pouring and curing; formwork removal; construction of grade beams and flooring sub-base

Foundation acceptance inspection; verification of anchor bolt elevation, spacing, and verticality

III. Steel Structure Prefabrication (Concurrent with Civil Works to Save Time)

Steel processing takes place at the factory while civil foundation work is underway:

Raw material inspection: Verification of quality certificates for H-beams, steel plates, profiles, welding rods, and paint

Cutting and fabrication: Assembly and welding of H-beam columns, roof beams, and crane beams

Correction, drilling (bolt holes), and shot-blasting for rust removal

Anti-corrosion coating: Primer, intermediate coat, and topcoat; application of fire-retardant coating if required

Component labeling, packaging, loading, and transport to the construction site

Concurrent fabrication of accessories: Wall and roof purlins, tie rods, bracing, gutters, flashing, door/window frames, and color-steel sandwich panels

IV. Main Steel Structure On-site Installation (Core Process)

Re-surveying foundations, cleaning anchor bolts, and placing base plates

Hoisting steel columns into position, tightening anchor bolts, securing with temporary bracing, and adjusting for verticality and elevation Install crane beams (for facilities equipped with overhead cranes)

Hoist and install main roof beams (portal rigid frame steel beams); bolt them to steel columns to form the rigid frame

Install horizontal bracing, inter-column bracing, and tie rods to create a stable, integrated structure

Install roof and wall purlins; fasten all high-strength bolts and verify torque specifications

Conduct overall structural acceptance inspection (checking verticality, deflection, and bolt tightness)

V. Building Envelope Installation (Roofing & Walling)

Roofing: Install color-coated steel sheets or rock wool sandwich panels; install skylight strips, roof ventilators, ridge caps, and gutters

Walling: Install wall panels, doors, and windows; install edge trims/flashings and rainwater downpipes

Waterproofing: Apply weather-resistant sealant to panel joints; seal ridges and gutters to prevent leakage

VI. Flooring and Ancillary Civil Works

Interior Flooring: Lay crushed stone base and steel mesh; pour and cure wear-resistant or epoxy flooring

Ancillary Civil Works: Boundary walls, main gates, perimeter aprons, drainage ditches, loading docks (for logistics warehouses), and equipment foundations

Septic tanks, fire water reservoirs, and paved roadways

VII. MEP, Fire Protection, and Ancillary Equipment Installation

Electrical: Power distribution room; install cable trays along the steel structure; lighting, sockets, and crane power circuits

Plumbing: Plant-wide water supply, drainage, and rainwater piping networks

Fire Protection: Fire hydrants, sprinkler systems, smoke detectors, smoke exhaust systems, and fire-rated compartment sealing

Additional Equipment: Installation and commissioning of overhead cranes, fans, dust collection systems, surveillance systems, and ventilators

VIII. Finalization, Testing, and Completion Acceptance

General Remediation: Touch up damaged paint, repair wall panel gaps, and clean the site

Specialized Testing: Steel structure flaw detection, fire-retardant coating thickness inspection, fire safety acceptance, and lightning protection inspection

Compile complete set of as-built drawings, material certificates, and test reports

Five-party acceptance (Owner, Designer, Supervisor, Contractor, Geotechnical Surveyor); complete project filing and handover for operation