Guide · Building Components
C-purlin or Z-purlin?
It's about the lap.
Both are cold-formed secondary framing for metal-building roofs and walls. Z-purlins overlap at the splice for continuous spans; C-purlins butt at their supports.
The difference
Two shapes, two jobs
C-Purlin
The C-shape butts at supports — used for eave struts, base and header members, and framed openings where members don't need to overlap.
Z-Purlin
The Z-shape nests and overlaps at the lap, creating continuous-span strength across multiple bays — the standard for metal-building roof runs.
Rolled to spec
We roll both C and Z purlins up to a 24-inch web on our Maricopa line, cut to your run.
Which to choose
Continuous roof runs → Z.
Eave struts and openings → C.
Multi-bay roof framing wants Z-purlins for the overlapping lap; eave struts, end bays, and framed openings use C-purlins. Send the building and we'll roll the right profile and web depth.
Still not sure?
Tell us the job — we'll spec it
Send us what you're building and we'll match the right product and get you a quote within one business day.