23-Meter Cambered Roof Beam: No Sag, Just Clear Span

Welded H-section roof beams are the primary horizontal members supporting roof structure and loads. Below is GKL1-1 roof beam from an actual fabrication drawing.

Basic Specs

Construction Details

• Web: 10 mm thick
• Flanges: 16 mm thick × 200 mm wide
• End plates: PL20×180 and PL20×400
• Welding: equal-strength groove weld between web and flanges
• Camber: 70 mm upward at midspan, offsetting dead load deflection

Advantages

1. 23 m long span — single beam spans 23 meters, no intermediate columns
2. Cambered to offset sag — 70 mm pre-camber means roof stays level under load
3. Full penetration welds — class 2 welds ensure structural integrity
4. Q355B strength — higher yield than Q235, lighter section for same span
5. Custom depth — 572 mm deep section optimized for 23 m span

Disadvantages / Limitations

1. Heavy to lift — 23 m long beam needs large crane for erection
2. Transport length limit — 23 m length exceeds standard truck length, needs special permit
3. Deep section — 572 mm height reduces ceiling clearance
4. Camber precision matters — wrong camber means roof slopes wrong way
5. Weld inspection required — class 2 welds need ultrasonic testing

Typical Applications

1. Portal frame factory roofs — main rafter beam in steel plants
2. Warehouse long-span roofs — 23 m clear span warehouses
3. Aircraft hangar roofs — wide hangar door opening
4. Exhibition hall roofs — column-free exhibition space
5. Sports arena roofs — large span indoor sports venues

Fabrication Notes

• Web and flanges CNC cut, then welded by automatic submerged-arc
• Camber built in during fabrication, not straightened after welding
• End plates drilled to match column connection holes
• Surface blast cleaned, painted per specification

GKL1-1 welded roof beam — H572×200×10×16, 23 m long, 70 mm camber, Q355B, class 2 full penetration welds, built for long-span steel roofs.

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**Email**: eddie@zdsteels.com, wells@zdsteels.com