Whether you are renovating a home and office or constructing a new one, you must go through the ordeal of choosing the right materials. Especially for the roof, you need something durable that maintains its structural integrity for years to come. That’s where steel purlins come in. They maintain the stability of the roof and distribute the load evenly. If you want to know more about steel purlins, their types, and applications, keep reading!
What are Steel Purlins?
Steel purlins are lightweight, horizontal beams made of cold-rolled steel that span between the building’s main structural components (roof and walls). They easily carry the weight of the roof, panels, and additional loads from snow or rain, transferring it to the other parts of the building. More and more people are investing in purlins, which is why their global market size is expected to reach USD 4.71 billion by 2033.
Types of Steel Purlins
There are different types of steel purlins, including C- and Z-shaped, each with unique features that make them suitable for various applications. Let’s discuss these in detail:
C-Shaped
C-shaped steel purlins, as the name implies, are made of roll-formed galvanized steel and have a shape that resembles the letter C. They serve as the wall and flooring joists in building structures and also fortify the structural integrity of roofing systems.
You can get them in various sizes and lengths, allowing you to pick the one that suits your application. Statistics show that C-shaped purlins take up around 65% of the global purlin market. However, these purlins aren’t very sturdy and are suitable for smaller projects.
Here’s an overview of some sizes of C-shaped purlins:
Size | Thickness | Length |
102 × 51 × 12.5 | 1.5mm | 1m |
102 × 51 × 14 | 1mm | 12m |
102 × 51 × 14 | 1.5mm | 6m |
102 × 51 × 15 | 1.9mm | 12m |
102 × 51 × 15 | 1.9mm | 6m |
300 × 96 × 28 | 2.4mm | 1m |
102 × 51 × 13 | 1.2mm | 1m |
102 × 51 × 14 | 1.5mm | 1m |
102 × 51 × 15 | 1.9mm | 1m |
152 × 64 × 16 | 1.5mm | 1m |
152 × 64 × 16 | 1.5mm | 6m |
Z-Shaped
Z-shaped steel purlins, as their name suggests, have a Z-shaped form and are made from cold-formed and rolled sheets. They gave an angle that’s less than 90 degrees, providing them greater flexibility compared to C-shaped purlins.
Hence, you can use them for a variety of applications, including the building’s shell structures.
Despite their flexibility, they have high strength that enables them to support heavy structures. On top of this, these purlins can be overlapped and are built for longer spans. They are very easy to install, requiring less labor and skills.
Here’s an overview of the sizes of Z-shaped steel purlins:
|
Section Reference
|
Weight
kg/m
|
Area
cm²
|
Depth
mm
|
|
142 Z 13
|
2.84
|
3.62
|
142
|
|
142 Z 14
|
3.05
|
3.89
|
142
|
|
142 Z 15
|
3.26
|
4.16
|
142
|
|
142 Z 16
|
3.47
|
4.42
|
142
|
|
142 Z 18
|
3.89
|
4.95
|
142
|
|
142 Z 20
|
4.30
|
5.48
|
142
|
|
172 Z 13
|
3.25
|
4.14
|
172
|
What are the Benefits of Steel Purlins?
Steel purlins are known for their efficient load distribution on the roof and overall stability. Here’s a detailed explanation of the many benefits they offer:
Diverse Usage
Purlins are suitable for diverse structures, but their main usage these days lies in pre-engineered buildings that are becoming increasingly popular. In the US, the prefabricated housing market size is quickly growing, and it is expected to reach $ 60,272.9 million by 2033.
In addition to this, warehouses and parking spaces are also utilizing steel purlins, both C- and Z-shaped. It’s because they are easy to manipulate, and manufacturers can drill holes and openings anywhere during the framework assembly process.
Non-Combustible
Do you know that on average, fire-related incidents cause over 180,000 deaths worldwide annually? Unfortunately, it’s true! One of the major benefits of steel purlins is that they are non-combustible.
This is due to the steel material, which doesn’t burn or ignite, preventing the risk of fire and protecting all the people inside the building.
Even if there’s a fire nearby, these purlins cannot catch it, eliminating the chances of it spreading around. The non-combustible nature of this material is also beneficial when constructing a new building, as it allows you to employ steel purlins to comply with Fire Safety codes.
Lightweight
Steel purlins are also very lightweight because they are manufactured from thin sheets of cold-formed steel, which are pressed into C or Z shapes.
The process uses less material than hot-rolled, heavy-duty steel and results in a purlin that’s significantly thinner. This leads to quicker installation of purlins and easy transportation and handling.
Durability
Compared to other types of purlins, like wood ones, steel purlins are quite durable. Typically, they can last for anywhere from 20 to 50 years, depending on the area and upkeep. Their long lifespan ensures you don’t have to replace them often or tend to extensive repairing and maintenance, saving you money.
Finishes of Steel Purlins
Now that you are aware of the many benefits of steel purlins, it’s time to explore the various finishes they are available in:
-
Galvanized Purlins: A galvanized purlin is either a C- or Z-shaped purlin that is coated in a layer of zinc through a process called galvanization. This is achieved by dipping the purlin in molten zinc, which acts as a protective barrier against moisture, salt, and other corrosive elements.
-
Red Oxide Purlins: Red oxide purlins, as the name implies, are coated with red oxide primer. It prevents rust from accumulating on the steel’s surface during storage and transportation. While it’s not as corrosion-resistant as galvanized purlins, it still enhances the overall durability and is cost-effective.
Applications of Steel Purlins
Steel purlins have diverse applications from general commercial buildings to agricultural structures, canopies, and carports. Here’s an overview:
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Wall Girts: Used vertically or horizontally on walls to hold wall cladding sheets in place and provide stability.
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Industrial and Commercial Buildings: Critical in pre-engineered buildings, factories, and storage units, allowing large roof spans without heavy beams.
-
Agricultural Sites: Supports lightweight roofing sheets in farmhouses, poultry sheds, and barns.
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Solar Panel Mounting Frames: Z and C purlins are used to create support structures for solar panels on the roof.
How to Choose the Right Purlins for Your Applications?
When choosing the right steel purlins for your application, you need to consider multiple factors, such as load requirements and the correct size and thickness. Let’s discuss them in detail:
Determine Load Requirements
First things first, you should determine your load requirements, which is the total load the roof will carry. This includes the weight of the roofing material, such as insulation, roofing sheets, and fixtures (dead load), as well as snow, wind, and water (live load). For instance, if you live in a colder region, you need to get durable and thicker purlins that can easily withstand daily wear and tear without collapsing.
Choose the Right Purlin Type
Depending on the project at hand, you will need to choose between C- and Z-shaped purlins. If you are working on a small project, such as a workspace with small to medium spans and simple sheds, you should opt for C-shaped purlins. Nonetheless, if you are constructing a warehouse or a commercial building with larger spans and sloped roofs, then Z-shaped steel purlins are the right option.
Pay Attention to the Right Size and Thickness
Another thing you should be mindful of is the size and thickness of the steel purlins. The depth is the height of the purlin, and the greater the depth, the more suitable it is for larger spans. Typically, the thickness will range from 1.5 mm to 3 mm; we suggest choosing thicker purlins if the roof is heavier.
Other things to look for are the ease of installation and overall cost of the purlins to make sure the project expenses align with your budget.
What Affects the Cost of Steel Purlins?
The overall purlins price is affected by material thickness, size, and span capacity. Additionally, coating on the steel (Galvanized or Red Oxide) and transportation also influence the overall. In some cases, when there’s a political conflict going on, the trading barriers can also impact the price.
Conclusion
Steel purlins are indeed a great investment if you want a strong roof. Wondering where you can get top-quality purlins that match the highest standards? Zhaojian Steel is a one-stop shop. Get in touch with us today and make your construction projects a breeze!
