By QED Consulting Engineers — structural & civil engineers, Notting Hill, Melbourne
Warehouse structural design typically combines a portal frame — the primary steel structure — with a slab and footings, often tilt-up or precast concrete walls, and frequently a mezzanine. Each part has to work together to create a large, column-free space that's efficient to build and to use.
Here's how warehouse structures come together.
What is a portal frame?
A portal frame is a rigid steel frame of columns and rafters connected by moment-resisting joints. That rigidity lets it span wide, column-free spaces — ideal for warehouses, factories and workshops. Frames come in several forms — single-span, multi-span, mono-pitch and others — chosen to suit the building's width, height and use. Secondary steel such as purlins and side rails carries the roof and wall cladding between frames.
Portal frame vs tilt-up concrete
Many warehouses combine the two: a steel portal frame for the primary structure and tilt-up or precast concrete panels for the walls, which provide durability, security and fire resistance. The right mix depends on span, height, fire requirements, budget and program. The engineer designs how the frame and panels work together.
Slabs, footings and openings
The warehouse slab carries forklifts, racking and stored goods, so it's designed for those loads. Footings — often pad footings under the columns — anchor the frame and resist the forces it transfers to the ground. Large roller-door and dock openings interrupt the wall structure and need careful framing around them so loads are redirected safely.
Mezzanines and extra space
A mezzanine adds a raised floor for offices or storage inside the shed, making better use of the volume. Mezzanines are designed for their intended load and integrated with the primary structure (more in our mezzanine guide).
Our commercial and industrial engineering team designs warehouses and industrial buildings across Melbourne and Victoria.
Planning a warehouse or industrial build? Talk to a Melbourne structural engineer.
Frequently asked questions
What span can a portal frame achieve? Portal frames can span wide, column-free spaces, with the achievable span depending on the frame type, loads and design. The engineer determines the right configuration.
Portal frame vs tilt-up — which is better? They're often combined — steel portal frame for the primary structure, tilt-up or precast panels for the walls. The best mix depends on span, height, fire requirements and budget.
How are warehouse footings designed? Usually as pad footings under the columns, sized for the loads the frame transfers and the site's soil conditions.
Do I need an engineer for a warehouse or large shed? Yes — the portal frame, slab, footings and openings all require structural design to the relevant standards and for the permit.
