During the construction of metal buildings or steel structural buildings, we always use steel purlins! Among the popular c and z steel purlins, we may have questions about which one to use. Therefore, regarding this, we will give some brief introduction in the article.

metal building with c and z steel purlinsFirstly,  a purlin is a horizontal beam or bar used for structural suppport in buildings, most commonly in a roof.  Several kinds of purlins exist. People like to divide them into categories based on their material and shape.  The purlin most commonly used in roofing is the steel purlin. Nowadays, we produce  “C” and “Z” (Cee and Zed) shaped channels via cold forming from high-strength zinc-alloy coated steel with minimum yield stress 60% higher than the respective profiles formed through hot forming.  This means that we can use sections of minimum thickness and weight, resulting in reduction of the time and the cost of the construction.

And then, people tend to use C and Z steel purlins on their steel framed buildings, in order to provide an efficient, lightweight and cost efficient roofing, cladding and walling support system (Purling and girt system). 

However, there is always a question: Shall I use C steel purlins or Z steel purlins on my building? Is there any other difference only except for the shapes?

c and z steel purlins

As a result, let’s take a look into the mysteries of the choosing between C and Z steel purlins.

Technical characteristics of C and Z steel Purlins:

Dimensions of C and Z Shaped Steel Purlins:

C AND Z STEEL PURLINSThe “C” and “Z” shaped sections have  standard dimensions (Web height:80-300mm; Flange size: 50-80mm; Leg Size:15-30mm). You can have any cutting length from 1.000mm to 20.000mm according to the engineering design data.  The designed punching holes are also available with the following restriction:
• Minimum distance from the end section 35mm
• Minimum centre holes distance in perpendicular axe 65mm.

Z Shaped Profiles:

The “Z” shaped sections structural elements feature two flanges of different width! In this way, two elements with the same static height can overlap, fitting perfectly to each other.
As a result, we achieve to bridge multiple spans with continuous Z purlins. 

C Shaped Profiles:

The “C” shaped sections structural elements feature two equally sized flanges and are ideal for structural support in walls and as floor joists in addition to roofs. Furthermore, we can use Cee also to form braces, ties or columns in sheds.

Applications of C and Z Shaped Section Channels:

  • Since the moment of inertia on Z purlin’s weak axis is much bigger than that of C purlin, Z purlin works much better from the integrity point of view.
  • Z steel purlins can be overlapped continuously while C steel purlins cannot, therefore, it’s better to use Z steel purlins instead of c purlins on metal buildings with continuous spans.
  • Z purlins are much stronger than C purlins due to its continuous or overlapping capability. In this case, for the metal building with bigger roofing loading capacity.
  • On the roofing of steel framed structures with single spans, and for supporting walls, it’s better to use Cee purlins because it’s easy to install and calculate. On wa the can work as supporting for roof, walls and floor etc.
  • For the metal buildings installed with concealed fixing or klip lok roof panels, Z purlins can work better than C purlins.

All the above information may help you to choose the right steel purlins for your buildings. In case you are interested in roll forming machines for manufacturing C and Z shaped by your own, you may want to visit our pages here.