C and Z sections are both important parts of your structure, allowing us to fix material to the roof and walls in order to create the finished structure.

C and Z sections are generally used as roof purlins or wall girts, helping to create the main ‘skeleton’ of your building that other materials are fixed to.

All our structural steel buildings use heavy RHS I and H beams, along with web trusses formed out of RHS & SHS. However, C and Z sections are also used as a lighter alternative for specific areas where load-bearing is less of an issue, and a reduction in overall weight benefits the final structure.

Reducing the weight of the building means less steel, and less material cost – you can save money through efficient structural engineering.

What are C Sections Used For?

As the name suggests C purlins are shaped like the letter C and are generally used to support walls and floors. They are used to shape the shell of the building, creating a skeleton on which to construct the walls of the structure.

Made from roll-formed steel, these purlins are usually 1mm to 3mm millimetres thick, making them lightweight but not as strong as structural steel.

C sections are always used at the eave to support the guttering, and in smaller sheds with bays under 6m wide, C sections can be used as support beams.

What Are Z Sections Used For?

Z purlins are somewhat stronger than C purlins due to their interlocking shape. They are typically used at joints and overlaps, giving structure to the roof and wall joists. Z purlins function as roof and wall purlins and girts, sitting between the COLORBOND sheets and the building. They act as a support to securely fix the cladding in place.

Because they can be overlapped, steel Z sections can overlap portal frames to brace the bays and allow for smaller Z sections. They can also be used in a more flexible manner, as unlike C sections, they can be fixed at different angles. C sections can only butt up against the frame, whereas Z sections can be oriented in different ways to achieve different structural outcomes.