Structural steel erection is the on-site assembly and installation of fabricated structural steel components — columns, beams, trusses, and connections — into the final structure. It is a specialist activity requiring experienced erection teams, appropriate lifting equipment, and systematic planning to ensure safety, accuracy, and programme delivery. This guide covers the steel erection process, safety requirements, IS standards, and what to look for in a steel erection contractor India.
What Is Structural Steel Erection?
Steel structure erection begins after fabricated components arrive on site piece-marked and in erection sequence. The erection contractor lifts, positions, aligns, and connects each piece to form the complete structural frame — from column base plates grouted to foundations through to the final roof purlin. Erection is complete when the structure is plumb, level, braced, and all connections are fully bolted or welded to the engineer’s specification.
Steel Erection Process — Step by Step
- Pre-erection survey: Survey of anchor bolt positions and foundation levels before any steel arrives on site. Errors found before erection are cheap to fix; errors found after are expensive.
- Base plate grouting: Column base plates set to correct level and position, grouted with non-shrink cementitious grout. Grout must reach full strength before column loads are applied.
- Column erection: First lift — columns installed, plumbed, and temporarily braced. Plumbness tolerance: H/1000 or 6mm, whichever is greater (IS 7215).
- Beam and bracing installation: Primary beams, secondary beams, and bracing installed in erection sequence. All connections initially snug-tightened.
- Alignment and levelling: Frame checked for plumb, level, and grid alignment before final tightening. Corrections made by adjusting shims or re-lifting members.
- Final bolt tightening: All bolted connections torque-tightened to specification. HSFG (High Strength Friction Grip) bolts tightened to snug plus turn-of-nut or torque-wrench method.
- Weld completion: Site welds completed where specified — typically moment connections, splice plates, and shear studs.
- Inspection and sign-off: Dimensional survey of completed frame. Weld visual inspection and NDT. Bolt torque spot-checks. Engineer’s inspection and approval before sheeting or cladding.
Lifting Equipment for Steel Erection
| Structure Type | Typical Crane | Capacity Range |
|---|---|---|
| Light industrial shed (up to 12m) | Mobile hydraulic crane | 30–50T |
| Standard industrial building (12–20m) | Mobile hydraulic crane | 50–100T |
| Heavy industrial / tall structure (20–40m) | Mobile hydraulic or crawler crane | 100–300T |
| High-rise steel frame | Tower crane + mobile assist | Tower crane 6–12T hook |
| Long-span truss (40–80m) | Two cranes tandem lift | 100–500T combined |
Steel Erection Safety Requirements in India
- IS 7969:1975 — Safety code for handling and storage of structural steel.
- IS 3696 Parts 1 & 2 — Safety code for scaffolds and ladders.
- NBC 2016 Part 7 — Construction safety requirements.
- Factories Act 1948 — Applicable to construction sites classified as factories.
- All erection workers must have fall protection (harness and lanyard) when working above 2m.
- Crane lift plans required for all lifts above 80% of crane rated capacity.
- Tandem lifts require a specific lift plan approved by a competent person.
IS Standards for Steel Erection Tolerances
- IS 7215:1974 — Tolerances for fabrication and erection of structural steel.
- IS 800:2007 Clause 15 — Erection requirements including plumbness, alignment, and connection completion sequence.
- Column plumbness: H/1000 or 6mm maximum (whichever is greater) measured at any floor level.
- Beam level: ±3mm across the span for beams supporting cranes; ±6mm for other beams.
Heavy Fabrication and Erection for Industrial Projects
Heavy fabrication refers to the manufacture of large, high-tonnage structural steel components — typically individual pieces above 5 tonnes — requiring specialist handling, heavy-lift cranes, and large-capacity welding equipment. Heavy fabrication applications in India include:
- Large plate girders for bridges and transfer structures (10–150T per girder)
- Heavy built-up box columns for high-rise and industrial frames
- Large trusses for stadiums, hangars, and long-span roofs
- Equipment skids, pressure vessel supports, and reactor support structures
- Heavy crane girders and end carriages for high-capacity EOT cranes
- Offshore and marine structural modules
Equipment Platform Fabrication
Equipment platforms are elevated structural steel platforms that support process equipment — vessels, columns, heat exchangers, compressors, pumps, and filters — at the operating level required for process flow and maintenance access. Equipment platforms are common in refineries, petrochemical plants, pharmaceutical manufacturing, power plants, and food processing facilities.
Key considerations in equipment platform fabrication: floor load capacity must accommodate equipment weight plus live loads for maintenance and access; platform geometry must allow equipment removal without dismantling the structure; handrails, kickplates, and non-slip surfaces to NBC 2016; and connections to equipment nozzles or anchor bolts must match the equipment GA drawings exactly.
Steel Structure Erection and Heavy Fabrication — Suncorporation
Suncorporation Fabricators & Engineers provides complete structural steel erection services across India — from light industrial shed erection to heavy plate fabrication and erection of complex industrial frames. We fabricate in our own workshop and erect with our own team — no subcontracting of either scope.
Our erection services cover Hyderabad, Bengaluru, Chennai, Mumbai, Delhi NCR, and Kolkata. Contact us with your project scope for a fabrication and erection quotation.