What are roof purlins?

Roof purlin, also known as purlin and truss, is a horizontal roof beam perpendicular to the roof frame or rafter to support the rafter or roofing material. Roof purlin is a transverse bending (usually bi-directional bending) member, and is generally designed as a single-span simply supported purlin. The commonly used purlins are solid web type and light steel joist type.

roof purlins

1、Channel steel purlin

There are two kinds of channel steel purlin: ordinary channel steel purlin and light channel steel purlin. Ordinary channel steel purlin can’t give full play to its strength because of the thicker thickness of the profile, and the amount of steel used is larger. Although light channel steel purlin is improved than ordinary channel steel purlin, it is still not ideal.

2, Angle steel purlin

Angle steel purlin, ordinary angle steel purlin is convenient to take material, but the stiffness is poor, the amount of steel is larger, only applicable to the span, purlin distance and the load is small.

3、Combination Channel Purlin

Combination channel purlin is welded by two angles. Its steel consumption is less than ordinary channel steel, but the welding workload is large, suitable for span ≤ 4m.

4、Combination Z-shape steel purlin

Combination Z-shape steel purlin is similar to combination channel steel purlin, also welded by two angles. When the slope of roof i≥1/3, it is more reasonable than the section force of channel steel. 1, channel steel purlin

Channel steel purlin is divided into two kinds of ordinary channel steel purlin and light channel steel purlin, ordinary channel steel purlin can’t give full play to the strength because of the thickness of the profile, and the amount of steel is larger. Although light channel steel purlin is improved than ordinary channel steel purlin, it is still not ideal.

5、Hot rolled thin-walled H-beam and high-frequency welded thin-walled H-beam purlin

Hot rolled thin-walled H-beam and high-frequency welded thin-walled H-beam (hereinafter referred to as “thin-walled H-beam”) is a new type of lightweight steel, with a thin web, bending stiffness is good, the two main axes of the direction of the moment of inertia is close to the flange is straight and easy to connect and other advantages.