The quality of a billboard structure is decided in the workshop. Weld preparation, fit-up, distortion control and surface preparation are all invisible once the steel is galvanised or painted and standing in a field, but they decide whether the structure behaves as designed and how long its coating lasts.
This page describes how we fabricate billboard steel and what you can expect to see on a quotation.
Typical specifications
- Materialsstructural tube, plate, angle and sections to the design
- Cuttingprofiled base plates, flanges and splice plates; drilled bolt holes
- Weldingprepared and fitted joints, with load-carrying welds checked
- Access itemsladders, walkways, handrails and brackets made to fit
- Treatmenthot-dip galvanising or blast and paint, confirmed on your quotation
- Fastenersbolts, nuts and washers treated to match the structure
- Deliverymarked sections packed for road transport and crane lifting
From drawings to cut steel
Fabrication begins with the approved drawings. Tube, plate, angle and sections are cut to length, and base plates, flanges and splice plates are profiled. Holes for bolted joints are drilled rather than punched where fit matters, so that sections align on a crane hook without being forced.
For column structures the main tube is rolled or selected to suit, and for lattice work the members are cut and mitred so the frame can be assembled flat and checked.
Material selection follows the design. Heavier columns and head frames use thicker tube and plate, and secondary items like handrails and brackets use lighter sections. We keep records of what steel was used and where, so that repairs and later modifications can be matched to the original structure. Offcuts and waste are sorted for recycling.
Welding and assembly
Joints are prepared, fitted and welded to the design details, with fit-up checked before welding rather than corrected afterwards. Welds that carry load, such as column-to-base-plate and head frame connections, receive closer attention than secondary parts like handrail brackets.
Long sections are assembled in a jig or on a flat bed so that the straightness of the column and the alignment of splice flanges can be confirmed before the steel leaves the workshop.
Distortion is a known problem with welding long, thin sections, so welding sequences are planned and sections are held in jigs while they cool. Splice flanges are the critical case: if two flanges are not parallel, the bolts will pull the column out of line when it is lifted and joined. Checking the flange faces before treatment is what avoids that.
Ladders, walkways and brackets
Access items are fabricated alongside the main structure so they bolt on without drilling or cutting on site. Ladder stiles and rungs, walkway frames and grating, handrails, toe boards, lighting brackets and cable trays are made to fit the specific structure, not selected from a stock catalogue.
Details are covered on the billboard structures page.
Walkway grating and handrails are galvanised or painted to match the main structure, and fixing lugs are welded in the workshop so no hot work is needed on site once the coating is on. Cable trays and conduit supports are added for lighting and power, and a provision for cable entry is included at the base for structures with lighting or digital faces.
Galvanising and painting
Where the section fits the galvanising bath, the steel is hot-dip galvanised after fabrication, which coats it inside and out. Sections that are too large, or that need a colour, are blasted and painted with primer and finish coats. Bolts, nuts and washers are treated to match.
After fabrication, vent and drain holes must be correct for galvanising to work, so they are detailed before the steel is cut. Coating choice and responsibilities are confirmed on your quotation.
Surface preparation before painting includes blasting or cleaning to a standard suited to the coating system, followed by a primer and finish coats applied to the thickness the system requires. Edges, welds and bolt holes get particular attention because coatings thin out on sharp edges. After galvanising, any ungalvanised areas are repaired with zinc-rich paint.
Trial fit and delivery
Where practical, major joints are trial-fitted before treatment. Sections are marked, packed with their bolts and delivered in lengths that suit road transport and the crane planned for site. Related reading: billboard construction and billboard structural design.
Marked sections make site work quicker. Each piece carries a reference matching the erection drawing, bolts are bagged by joint, and a packing list travels with the load. If the structure is to go by road to another province or across a border, the loading plan and any special transport requirements are confirmed at quotation, together with duties and permits where they apply.
At a glance
Steel fabrication for billboards at Billboards Africa covers the cutting, welding, assembly and treatment of the steel that carries your face. We fabricate unipole columns, lattice frames, gantries, head frames, ladders, service walkways and lighting brackets, then protect them with hot-dip galvanising or blasted and painted systems.
Good steel fabrication for billboards starts with accurate fit-up, drilled bolt holes and straight sections, so that a mobile crane can lift the column onto its anchor bolts without forcing it. We deliver marked, packed sections to sites in Gauteng, KwaZulu-Natal, the Western Cape and beyond, and can fabricate replacement parts to match an existing structure. Engineering design and sign-off are arranged as the structure and site require. Send your drawings or site details through the quote form to request a quotation for billboard steel fabrication in South Africa. Fabrication scope, treatment and delivery are set out on your quotation. Whether you need a complete new structure or a replacement ladder, walkway or frame for an existing billboard in Soweto, Boksburg or Bloemfontein, we can fabricate it to fit and treat it to last.
Common questions
Do you fabricate to my drawings?
We can fabricate to drawings you supply after reviewing them. Engineering design and sign-off are arranged as the structure and site require.
Galvanising or paint?
Galvanising suits sections that fit the bath. Painted systems suit oversize parts, colour needs and repairs. We recommend by site and structure.
Can you fabricate only, without erection?
Yes, fabrication can be quoted separately. Say so on the quote form.
Do you fabricate repairs and replacements?
Yes. Damaged ladders, walkways, frames and brackets can be fabricated to match an existing structure.
Where is the steel delivered?
To site anywhere in South Africa, and further afield with transport, duties and permits confirmed per project.
