Over the years we have seen and used numerous purlin types. Each has its pros and cons depending on your budget and requirements.
In this article, we will review the pros and cons of key purlin types so you can be informed when deciding what purlin type is best for your next industrial building project.
A purlin is a horizontal framing member, usually spanning between rafters or portals, and provides support for the roof cladding.
You can view more building terms in our commercial building glossary.
Key types of purlins include:
The Steelbone purlin is an enclosed V-shaped purlin manufactured from a high-tensile galvanised steel coil.
With the above factors in mind, the Steelbone purlin is a great option for agricultural building uses where perching birds are a known problem as birds can cause significant damage to machinery and valuable products.
It is also a suitable option for open buildings or industrial canopies where birds have unlimited access to the building. This is because the Steelbone purlin system prevents birds from being able to perch in the rafter space.
If you're looking for a building with clean lines, is aesthetically pleasing, and has an architectural look, Steelbone purlins are a great choice.
Typically this purlin option wouldn’t be for someone who is looking for the cheapest purlin option and doesn’t see the value in the above advantages.
The C section purlin is one of the most common purlin profiles used for large-scale industrial building projects.
This is a high-tensile galvanised steel profile and is available in sizes from 150-400mm deep and in a variety of gauges to suit the engineering requirements of the building.
The C section purlin also has a range of name abbreviations depending on the supplier. These include MC purlins, CLR purlins, and DHS purlins.
The C section purlin is a great option for industrial buildings and commercial buildings where it is important to optimise the building's design efficiencies and where birds are not likely to be an issue.
Timber purlins are less common in the industrial building market however Attika's parent company Alpine Buildings NZ Ltd typically use timber purlins in their farm storage buildings and lifestyle buildings.
Attika has utilised the timber purlin successfully in a number of industrial workshops across New Zealand. These applications have had up to 6m wide bays which optimises the number of truck bays that can be designed into the building length and keeps within the parameters of the timber purlin.
Timber purlins are a great option for noisy workshops as it softens the sound and gives an ambient feel. Timber purlins are not a suitable option when looking to maximise the bay widths.
The RHS (rectangular hollow section) purlin is a structural steel purlin and would be considered a premium purlin option. This option would typically be used in the building design where other purlins don’t meet the engineering requirements.
Typically the RHS purlins are used in applications where the roll-formed purlins (c section purlins) cannot meet the engineering design requirements for particular locations of the building or to gain larger spacing between purlins.
The Tophat purlin is often seen used on lightweight roll-formed buildings.
Image sourced from Metalcraft.
Image sourced from Shed Boss.
In conclusion, there are a number of purlin types available. As explained, the purlin that will best suit your next project will depend on your specific project requirements and priorities.
If you are in the process of planning a new industrial or commercial building you may also be interested in our articles on the most efficient way to design an industrial building or the cost per m² of a commercial or industrial building. Alternatively, please feel free to reach out to the team directly.