C Purlins & Z Purlins
Cold-Formed to Project Specs

C purlins have a C-shaped cross-section and are typically used with simple lap connections at supports, suitable for moderate spans and spacing. Z purlins have a Z-shaped cross-section with overlapping flanges that allow continuous lapped connections at supports, providing better continuous beam bending performance and higher load capacity for wide-spacing roofs. Z purlins are generally preferred for larger spans and heavier loads.

Purlin size and spacing are determined by: roof slope, snow/wind loads, purlin span (distance between primary frames), cladding type and thickness, and applicable design codes. Common sizes range from C100 to C300 and Z140 to Z300, with typical spacing of 1.0m to 1.5m. The exact sizing should be specified in the structural design drawings.

Common surface treatments include: hot-dip galvanized (for corrosion resistance in exposed or humid environments), pre-painted / color-coated (for visible applications and additional corrosion protection), and bare / mill finish (for interior or protected applications). The treatment is specified based on project environment, coating system and architectural requirements.

Yes. ZhongSai supplies purlins with pre-punched connection holes based on shop drawings, including holes for purlin-to-rafter connections, sag rod connections, and lap splice connections. Pre-punched purlins reduce on-site drilling work and improve erection accuracy. Please provide the purlin layout and connection details for hole positioning.