Two Very Different Products That Do a Similar Job
Walk into any structural steel supplier in Sydney and you will find both universal beams and welded beams on the price list. To a homeowner or someone new to construction, they might look similar — both are I-shaped steel sections used to carry loads. But to a structural engineer, the choice between them is deliberate and technically significant. Using the wrong one does not just affect cost; it affects the structural performance of your building. Cedar Steel fabricates both universal and welded sections in-house at its Bankstown workshop, supplying builders and engineers across Sydney and NSW.
What Is a Universal Beam?
A universal beam, commonly abbreviated to UB, is a hot-rolled steel section with an I-shaped cross-section. The web (the vertical plate in the middle) is deeper than it is wide, and the flanges (the horizontal plates top and bottom) are parallel. This geometry is specifically designed to resist bending when the beam is installed horizontally — which is exactly what happens when a beam spans between two columns, carries a floor above it, or supports a roof.
Universal beams are produced in a rolling mill from a solid billet of steel. They come in standard section sizes, typically referenced by their depth and weight per metre — for example, a 310UB40.4 is approximately 310 mm deep and weighs 40.4 kg per metre. Standard lengths in Australia typically range from 9 m to 20 m, with non-standard lengths available from fabricators like Cedar Steel on request.
Because they are manufactured to standard dimensions under tight tolerances, universal beams offer excellent predictability. Your engineer can specify exactly which UB section is required and know precisely what strength and stiffness they are getting.
What Is a Welded Beam?
A welded beam, abbreviated to WB, is not rolled from a billet. It is fabricated by welding three separate steel plates together — two flanges and a web — to create an I-shaped section. Because the plates can be cut to any dimension before they are welded, welded beams can be produced in sizes and proportions that are not available in the standard universal beam range.
This matters enormously on large-span or heavily loaded structures. When a universal beam simply is not deep enough, wide enough or heavy enough to carry the required load, the engineer specifies a welded beam with custom plate dimensions. Heavy commercial buildings, long-span warehouse roofs, multi-storey residential frames and major infrastructure projects are all common applications.
Welded columns (WC) follow the same principle — fabricated from three plates — but are proportioned for axial compression rather than bending. Where universal columns (UC) reach their limit, welded columns step in.
How Does the Fabrication Process Differ?
Universal beams arrive at a fabrication workshop already rolled to size. The fabricator’s job is to cut them to length, cope and notch them for connections, drill bolt holes and weld on any connection plates or cleats. This is efficient and fast — the material cost is predictable and the fabrication work is focused on detailing rather than section creation.
Welded beams require the fabricator to source three plates, cut them to the specified dimensions, set them up in a jig and weld them together with a continuous fillet or butt weld along each flange-to-web junction. This is more labour-intensive and requires a higher standard of welding to comply with AS/NZS 1554. The result is a bespoke structural section built to the engineer’s exact specification.
Cedar Steel fabricates welded beams and welded columns in-house at its Bankstown workshop, alongside the full range of standard universal beam and column work. Both product types move through the same quality control process before dispatch.
When Should You Use a Universal Beam?
Universal beams are the right choice in most standard residential, commercial and light industrial applications across Sydney. If your engineer’s design calls for spans and loads that fall within the published standard section tables, a UB is almost certainly the most cost-effective and time-efficient option. Explore the full range of structural steel beams in Sydney that Cedar Steel supplies and fabricates.
Common UB applications in Sydney construction include: floor and roof beams in residential extensions and new builds, portal frame members in light commercial and industrial sheds, inter-tenancy beams in commercial fit-outs, lintel beams over wide door and window openings, and mezzanine floor beams in warehouse and office environments.
When Do You Need a Welded Beam Instead?
Your engineer will specify a welded beam when the loads or spans exceed what the standard UB range can accommodate, or when the structural geometry requires a section that cannot be achieved with a rolled product. This typically occurs in heavy industrial work, large-span commercial steel construction in Sydney, multi-level residential structures and major civil or infrastructure projects.
If you receive a specification from your engineer that calls for a WB or WC section, it is not interchangeable with a similarly sized UB or UC. The section properties are different and substituting without engineering approval creates a compliance and liability issue.
What Does This Mean for Lead Times and Cost?
Universal beams are stocked products. Lead times from order to dispatch are shorter because the raw material is available and the fabrication work is limited to detailing. Welded beams require plate procurement and fabrication from scratch, which takes longer and carries a higher material and labour cost.
For projects with tight programmes, it is worth getting your drawings to Cedar Steel as early as possible. Cedar Steel can advise at quote stage whether your specification requires welded sections and factor the lead time into your delivery schedule. Quote responses are turned around within one business day.
Talk to Cedar Steel About Your Beam Specification
Whether your project calls for standard universal beams, custom welded beams, or a mix of both, Cedar Steel has the in-house capacity to supply, fabricate and deliver the right steel for your build. Steel installation and erection in Sydney is also available for projects that require an end-to-end solution. Operating from Bankstown, Cedar Steel services builders, engineers and project managers across the full Sydney metropolitan area and wider NSW.
Get the steel right from the start. Send your drawings or call to discuss your specification and we will have a quote back to you within one business day.
Contact Cedar Steel:
Visit: https://cedarsteel.com.au/contact/
Call: 1300 714 334
Cedar Steel. Built in the workshop. Proven on site. Serving Sydney-wide.
