The basics
Cold-formed sections (purlins, girts, light columns, cold-formed beams) are produced from coil and offer high strength-to-weight at low thickness. Hot-rolled sections (ISMB, ISLB, ISHB, plate girders) deliver brute capacity and connection robustness.
When cold-formed wins
- Secondary framing — purlins, girts, sag rods.
- Light mezzanines with low loads.
- Single-storey sheds with short spans.
- Roof and wall cladding sub-structures.
When hot-rolled wins
- Primary framing — main columns and rafters.
- Crane support framing — gantry girders and crane columns.
- Heavy industrial sheds with significant equipment loads.
- Multi-storey structures.
Where the line gets crossed
- Cold-formed used as primary framing in mid-size PEBs — works if connections and lateral stability are detailed correctly, fails when they are not.
- Hot-rolled used as purlins — over-engineered, but sometimes specified by owners for fire-engineering reasons.
MEC's stance
For every project we run a section-economy check that asks: would substituting cold-formed for a secondary member save material without adding installation cost? The answer drives the section schedule, not habit.
Lead-magnet download: Our cold-formed vs. hot-rolled application matrix — a one-page decision aid. Request the matrix.