purlins

Steel Purlins

What Are Purlins?

Purlins are considered secondary framing. They are commonly used for pre-fabricated metal construction. They sometimes are also referred to as “secondary structurals” and are essential to many large steel buildings. Their purpose is to distribute loads from the building’s outer surfaces. Then to the main framing and the foundation.

In steel construction, the term Purlins typically refers to roof framing members. They also span parallel to the building eave. Therefore they support the roof decking or sheeting. The purlins are in turn supported by rafters or walls. Purlins are most commonly used in metal building systems. Most commonly where Z-shapes are utilized in a manner that allows flexible continuity between spans.

What Is A Purlin Versus A Girt?

Purlins can be very similar to girts, but their uses are different. While purlins run the horizontal length of rafter structuring to support the roof, girls run in conjunction with columns and walls to provide wall support.

In short, a purlin is a secondary reinforcement for the roofing of a building. They provide additional mid-span support. This allows for wider buildings. The cross structure supports the building.

Girts provide additional support to the column of a structure that hold the walls. They provide additional siding support to withstand impact from wind and weather. This is so your building lasts longer. It also helps reduce noise.

What Types of Formations Are There?

Structural shapes are assigned representative designations. Therefore convenient shorthand descriptions on drawings and documentation. It is common practice in the steel industry. Channel sections with or without flange stiffeners are usually referenced as C shapes. Channel sections without flange stiffeners can also referenced as U shapes. Sections that are shaped similar to the letter Z are referenced as Z shapes.

Look for variations in the designs. Section designations can be regional. So they may also be specific to a manufacturer. Secondary members such as purlins (roof) and girts (wall) are frequently cold-formed steel. These include C, Z or U sections, (or mill rolled) C sections. Other variations exist.

Cold formed members can be efficient on a weight basis. In comparison to relative to mill rolled sections for secondary member applications. Additionally, Z sections can be nested for transportation bundling. They lap at the supports to increase strength. This is to develop a structurally efficient continuous beam across multiple supports.

Exactly how many and what size secondary framing elements you need may vary. Your building may require different purlins based on the building’s dimensions. The type of framing that is used can greatly affect the cost. It may be necessary steel supply to ensure safe construction though.

Get In Touch With Us Today

We carry purlins of all sizes. Most of the time we have what you need in stock. You can contact us online or call today to place an order.  So call (281) 499-5800 today. Large orders can be filled in a few short days.

Leave a Reply