Purlins vs Structural Steel
17 August 2021
Purlins vs Structural Steel: What You Need to Know
IN BRIEF
- When it comes to commercial and industrial buildings, structural steel is a better choice over lightweight purlins due to its superior strength and durability.
- Shed purlins made of lightweight steel sheets are prone to bending and twisting, making them unsuitable for heavy-duty applications.
- Structural steel buildings are made from hot-formed RHS steel members, providing greater structural integrity. They’re also more suitable for large spans.
- Structural steel can be customised making it more versatile compared to purlin structures which are limited to standard material sizes.
Structural Steel Offers Strength and Durability
When you’re building a new commercial structure, one of the main things to take into consideration is the longevity of the structure. One of the main components of building – steel – is one place where you don’t want to cut corners.
Choosing strong, durable materials may cost a little more initially but will save you in the long run, and that’s why we only use Australian structural steel. Here’s a breakdown of the differences between steel vs purlin sheds and why structural steel is the clear winner.
Strong, Durable, and Fabricated to Order
The purlins typically used in cheaper shed construction are made by cold roll-forming lightweight steel sheets into the desired C or Z purlin.
Often, the steel used to manufacture purlins is only 1mm – 3mm millimetres thick, making it much more flimsy and prone to bend and twist. This means purlin structures typically aren’t suitable for heavy-duty applications like storing machinery or industrial buildings. A minor bump or two and your structure could suffer damage that’s difficult to fix. Lots of bracing is required to get a requisite level of strength, but it still doesn’t compare to the rigidity of structural steel.
A structural steel building is made from hot-formed RHS steel members in H or I beam shapes. These universal steel beams can be up to 20mm thick and are welded and fabricated to order, as well as being hot-dip galvanized for corrosion resistance and durability.
Structural steel members and welded trusses are intrinsically stronger, making them more suited to large spans and bigger structures, whereas purlins simply don’t have the same structural integrity.
Installation Time
Although it would seem like structures with purlins are quicker and easier to install, they can actually take considerably longer to install as every piece has to be individually bolted together on site. The roll-formed sections need to be bolted to angle brackets and then bolted to the slab, meaning lots of labour time for the installation crew.
Plus, because the pieces are quite flimsy and flexible, they present their own installation challenges.
Contrast this with structural steel members that are engineered to the precise size required, and fabricated so that they can simply be erected on site. The prefabricated welded columns and trusses arrive ready to go and simply need to be lifted into place. The installation process still takes time of course, but is generally much faster than purlin construction.
The Ability to Customise Your Structure
Choosing structural steel means that you have the utmost control over the size and shape of your structure. Because each component is cut and welded to order, the possibilities are nearly endless, whereas purlins must be made from standard material sizes.
Additionally, purlins can really only be used up to about a 20-metre span, making them no good for larger industrial structures and commercial buildings. Structural steel spans can be much larger, meaning you can build a structure that works for you today and into the future, allowing for growth and changes in your business.
Safety and Approvals
If your site is in a high-wind area, a structure using purlins may not pass through the approval process as its limited structural strength makes it unsuitable for windy conditions.
The larger the structure, the more obvious this issue becomes, so if you’re located in an area that requires a high wind rating a structural steel building is the way to go.
Conclusion: Structural Steel is the Clear Winner Over Purlin
Whilst purlins are sometimes more cost-efficient for small backyard sheds, once you get into the commercial, industrial and agricultural structure space where larger buildings are commonplace, structural steel is the only sensible choice. It’s strong and robust, can be customised to your needs, and presents a lower labour cost due to its faster installation time.
An Australian Made Steelcorp structural steel building will provide you with the durability, design freedom and strength necessary for your commercial project. Give our friendly team a call for advice – we’re here to help.
