Z PURLIN
Z purlins resemble the shape of a letter "Z" and are also referred to as Zee or Zed purlins. They are roof framing members that span parallel to the building eave and support the roof decking or sheeting. The metal purlins are in turn supported by rafters or walls.
Z purlins or zed purlins are horizontal beams that are designed to form the roof and wall joists of a building shell structure. They sit between the roofing sheets and the building, acting as a support for the sheet to ensure it is firmly attached and safely in place.
Z purlins are most commonly used in agricultural and industrial buildings due to their extremely versatile and lightweight properties which make them easily adapted for use in a variety of different sized buildings.
Description | Unit | Purlin Size | ||||
Purlin Type | - | M5 'Z' | M4 'Z' | M3 'Z' | M2 'Z' | M1 'Z' |
Depth | mm | 222 | 202 | 172 | 151 | 130 |
Top | mm | 67 | 62 | 60 | 60 | 52 |
Bottom | mm | 67 | 62 | 60 | 60 | 52 |
Top Lip | mm | 23 | 23 | 21 | 20 | 18 |
Bottom Lip | mm | 23 | 23 | 21 | 20 | 19 |
Girth | mm | 383 | 363 | 325 | 303 | 263 |
Thickness | mm | 2.5 | 1.8 | 1.6 | 1.5 | 1.5 |
Ixx | cm4 | 740 | 381.61 | 234.53 | 179 | |
Zxx | cm3 | 66.1 | 37.271 | 28.863 | 23.33 | |
Ryy | cm | 3.46 | 2.799 | 2.944 | 3.08 | |
Iyy | cm2 | 121 | 49.653 | 44.86 | 46.93 | |
A | cm2 | 10.1 | 6.335 | 5.174 | 4.95 | |
Span | Ft | 30 | 24 | 20 | 15 | 12 |
Weight | kg/m | 7.59 | 5.12 | 4.18 | 3.81 | 3.17 |
Q. Which is stronger Z or C purlin?
A. Strength: Z Purlins are extremely strong and can support heavy structures although, C purlins have relatively less strength. Therefore, in buildings with a bigger roofing or loading capacity, Z purlins would be a better choice.
Q. How far can Z purlins span?
A. A four-inch purlin can span 12 feet. A six-inch purlin can span 18 feet. An eight-inch purlin can span 25 feet. A ten-inch purlin can span 30 feet.
Q. Why are purlins Z shaped?
A. 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.
Q. What size purlin should I use?
A. As per generals rule and guideline, you need a 4- inch (100mm) purlin for 3m span, 6- inch (150mm) purlin for 4m & 5m span, 8- inch (200mm) purlin for 6m & 10- inch (250mm) purlin for 8m span which can safely transfer the load to trusses.
Q. What is the minimum spacing of purlins?
A. In order for the sheets to be easily fixed to the purlins, as a rough guide they should be at least 50mm wide. When positioned, roof purlins should be spaced no further than 1.2 metres apart when using sheeting with a thickness of 0.7mm, and 1 metre when using 0.5mm sheeting.