Steel truss fabrication is a core structural steel service for industrial buildings, factory roofs, warehouse spans, and infrastructure bridges across India. A steel truss transfers loads through a network of triangulated members — top chord, bottom chord, and internal diagonals — allowing long spans without intermediate columns. This guide covers truss types, IS standards, fabrication process, and what to specify.
What Is Steel Truss Fabrication?
Steel truss fabrication involves cutting, fitting, and welding or bolting steel sections — typically hollow sections (CHS/RHS/SHS), angles, channels, or I-sections — into triangulated frames. These frames are designed to span large distances while carrying roof loads, equipment loads, or floor loads. In India, roof truss fabrication is the most common application — supporting industrial shed roofing, warehouse cladding, and factory buildings.
Types of Steel Trusses
- Pratt Truss: Diagonals in tension under vertical loads. Most common for industrial roof trusses in India. Spans 10–40m.
- Warren Truss: Equilateral triangles, no vertical members. Efficient for medium spans 15–50m. Common in pedestrian bridges and industrial roofs.
- Howe Truss: Diagonals in compression. Less common in modern fabrication.
- Fink Truss: W-shaped internal members. Very common for residential and light industrial roof trusses up to 20m.
- Parallel Chord Truss: Top and bottom chords are parallel — used for floor trusses and bridge decks.
- Pitched Roof Truss: Apex at centre, sloped top chord — standard for factory sheds, warehouse roofs, and industrial buildings in India.
- Space Frame / Space Truss: Three-dimensional truss system for very large spans — stadiums, aircraft hangars, and exhibition halls.
Steel Truss Fabrication — IS Standards
- IS 800:2007 — Design of steel trusses: member sizing, connection design, buckling checks.
- IS 2062 — Steel material: Grade E250, E350, or E410 depending on load and span.
- IS 1161 — Steel tubes (CHS/RHS/SHS) used for hollow section trusses.
- IS 816 / IS 9595 — Welding standards for truss joints.
- IS 875 Parts 1–3 — Dead, live, and wind load standards for truss design.
Steel Truss Fabrication Process
- Shop drawing preparation: Detailed fabrication drawings from structural engineer’s GA drawings — member sizes, joint details, weld symbols, bolt specifications.
- Material cutting: CHS/RHS sections cut to length by CNC plasma, oxy-fuel, or sawing. Cope cuts and mitre cuts for joint fit-up.
- Joint fit-up and jig assembly: Members assembled on a flat jig to maintain geometry and prevent distortion during welding.
- Welding: Fillet or butt welds at all joints. Critical joints (gusset plates, ridge connections) may require full-penetration welds with NDT.
- Inspection: Dimensional check against shop drawings. Visual weld inspection. DPT or UT at critical welds.
- Surface treatment: Blast cleaning Sa 2.5, primer, intermediate coat. Intumescent paint for fire rating where specified.
- Despatch: Piece-marked and loaded for site delivery in erection sequence.
Steel Truss Span and Weight Reference
| Span | Typical Truss Depth | Steel Weight (approx) | Common Use |
|---|---|---|---|
| 10–15m | 1.0–1.5m | 0.8–1.5 T/truss | Factory shed, warehouse |
| 15–25m | 1.5–2.5m | 1.5–3.5 T/truss | Industrial building, aircraft hangar |
| 25–40m | 2.5–4.0m | 3.5–8 T/truss | Stadium, large warehouse |
| 40–60m | 4.0–6.0m | 8–20 T/truss | Stadium roof, port shed |
Steel Roof Truss Fabrication for Industrial Sheds
The most common application of steel roof truss fabrication in India is for industrial sheds and factory buildings. A typical industrial shed uses pitched roof trusses at 5–6m centres, supported on steel columns or RCC columns, with purlins spanning between trusses to carry roof sheeting. Truss spans of 15–30m are most common for factory buildings. Trusses are fabricated from angles, channels, or hollow sections (CHS/RHS) depending on the load and the fabricator’s preference.
Steel Truss Fabrication — Suncorporation
Suncorporation Fabricators & Engineers fabricates steel roof trusses, industrial building trusses, and bridge trusses to IS 800:2007 across India. Our workshop handles spans from 10m to 60m+ with full weld inspection, dimensional checks, and blast + paint finishing. We supply fabricated trusses to projects in Hyderabad, Bengaluru, Chennai, Kolkata, Delhi NCR, and Mumbai. Contact us with your structural drawings for a truss fabrication quotation.