Z-Shaped Steel Purlin

Z-Shaped Steel Purlin Detail

A Z-purlin is a cold-formed steel section used as a secondary structural member in roof and wall systems. Its primary function is to provide support for the roof deck or wall cladding and transfer the loads (from wind, snow, and the weight of the sheeting) to the primary building frame (the main rafters, columns, or beams).

The "Z" shape is its defining characteristic, featuring two parallel flanges connected by a web, with one flange pointing in the opposite direction to the other.

Cross-section height (H): 100mm to 300mm (commonly used: 120mm to 250mm)

Flange width (B): 40mm to 70mm (upper and lower flange widths differ)

Angle of inclination (α): Typically 5° to 15° (for easy overlapping)

Plate thickness (t): 1.5mm to 3.0mm

Length (L): 4m to 12m (customizable)

Material: Q235B, Q355B, G550, etc., galvanized steel strip

Surface treatment: Primarily galvanized (hot-dip galvanizing, cold galvanizing), with optional spray coating or color coating for corrosion protection

Unique shape: The cross-section is Z-shaped, allowing for interlocking connections to enhance structural integrity.

Excellent load-bearing performance: Compared to C-shaped steel, Z-shaped steel better leverages its structural advantages in the arrangement of purlins on sloped roofs.

Suitable for large spans: High strength and rigidity make it ideal for large-span structures.

Convenient for transportation and stacking: Its shape allows for nested stacking, saving transportation space.

Roof and wall purlins for large industrial plants, warehouses, exhibition halls, etc.

Particularly suitable for structural systems with sloped roofs

As secondary structural load-bearing components between main and secondary beams

For roofs with a small slope and medium span: C-shaped steel purlins are recommended.

For roofs with a large slope or requiring overlapping construction: Z-shaped steel purlins are recommended.