Types of Purlins: Understanding Their Shapes, Applications and Uses in Steel Structures

Purlins are important structural components used in industrial buildings, warehouses, factories, commercial buildings and pre-engineered buildings (PEBs). They provide support to roofing and wall cladding sheets while transferring the loads to the main structural framework. Choosing the right type of purlin plays an important role in ensuring the stability, strength and performance of a building. Different purlin sections are designed for different structural arrangements and construction requirements. In this blog, we will explore the different types of purlins, their features, applications, advantages and how to choose the right purlin for your construction project.

What Are Purlins?

Purlins are horizontal structural members installed over the main roof beams or rafters of a building. Their primary function is to support roofing sheets and distribute the loads to the main structural framework. They are commonly used in industrial roofing systems, warehouses, factories, agricultural buildings and commercial structures.

Steel purlins are widely preferred in modern construction because they offer strength, durability, installation convenience and flexibility in design.

Different Types of Purlins Used in Construction

Purlins are available in different shapes and profiles depending on their structural applications. The most commonly used types include C purlins, Z purlins, U purlins, L purlins, Hat purlins and special section purlins.

1. C Purlins

C purlins are steel sections manufactured with a C-shaped cross-section. They are among the most commonly used purlin profiles in industrial and commercial construction.

Their simple design makes them suitable for various roofing and wall support applications. They are generally installed over structural beams to provide a supporting framework for roofing and cladding sheets.

Key Features:

• C-shaped structural profile.

• Simple and practical design.

• Easy handling and installation.

• Suitable for different roofing applications.

• Can be used in roof and wall framing systems.

Applications:

• Industrial warehouses.

• Factory roofing structures.

• Commercial buildings.

• Agricultural sheds.

• Wall cladding support systems.

2. Z Purlins

Z purlins feature a Z-shaped cross-section and are commonly used in large industrial buildings and pre-engineered building systems.

One of their important characteristics is their ability to overlap at structural support points. This makes them suitable for continuous-span roofing arrangements when properly engineered.

Z purlins are commonly preferred for projects where efficient structural arrangements and large roofing areas are required.

Key Features:

• Z-shaped structural profile.

• Suitable for overlapping arrangements.

• Useful in continuous-span systems.

• Lightweight structural design.

• Suitable for large roofing applications.

Applications:

• Large industrial sheds.

• Pre-engineered buildings.

• Manufacturing facilities.

• Large warehouses.

• Commercial and agricultural buildings.

3. U Purlins

U purlins are steel sections with a U-shaped cross-section. They are used in various secondary structural applications where an open-channel profile is required.

Their simple shape makes them suitable for different steel framing and supporting arrangements. They can also be customized according to specific project requirements.

Key Features:

• U-shaped cross-sectional design.

• Simple structural configuration.

• Suitable for secondary framing.

• Easy integration into different structures.

• Available for customized applications.

Applications:

• Industrial building frameworks.

• Secondary structural supports.

• Equipment support structures.

• Steel fabrication projects.

• Customized construction applications.

4. L Purlins

L purlins, also known as angle sections, feature an L-shaped cross-section. They are commonly used in structural support arrangements, bracing systems and steel fabrication work.

Their angle-shaped design makes them useful for supporting and connecting different structural elements in construction projects.

Key Features:

• L-shaped cross-sectional profile.

• Simple and versatile design.

• Useful for structural support applications.

• Suitable for different fabrication requirements.

• Can be incorporated into customized structures.

Applications:

• Structural bracing.

• Steel frameworks.

• Roof support arrangements.

• Industrial fabrication.

• Secondary structural components.

5. Hat Purlins

Hat purlins feature a distinctive hat-shaped cross-section. Their profile consists of a raised central section with outward-facing flanges.

They are used in selected roofing and cladding applications where their shape and fixing arrangement provide suitable support.

Hat sections are also useful in specialized secondary framing systems.

Key Features:

• Hat-shaped structural profile.

• Lightweight construction.

• Suitable for roofing and cladding support.

• Versatile design applications.

• Can be manufactured for specific project requirements.

Applications:

• Roofing support systems.

• Wall cladding structures.

• Industrial buildings.

• Secondary framing systems.

• Specialized construction projects.

6. Special Section Purlins

Special section purlins are customized steel profiles developed to meet specific construction and engineering requirements.

Unlike standard C, Z, U or L sections, these profiles can be designed with different cross-sectional shapes depending on the intended application.

They are particularly useful for projects that require customized structural solutions or unique profile designs.

Key Features:

• Customized cross-sectional shapes.

• Designed for specific project requirements.

• Flexible structural applications.

• Suitable for specialized construction.

• Adaptable to different framing requirements.

Applications:

• Specialized industrial structures.

• Customized roofing systems.

• Infrastructure projects.

• Complex steel frameworks.

• Unique architectural applications.

Difference Between C Purlins and Z Purlins

C purlins and Z purlins are two commonly used steel purlin sections in industrial construction. Although both serve the purpose of supporting roofing and wall cladding sheets, their shapes and structural applications are different.

C Purlins:

• Have a C-shaped cross-section.

• Commonly used in simple roof and wall framing arrangements.

• Suitable for various industrial and commercial structures.

• Relatively straightforward to install.

Z Purlins:

• Have a Z-shaped cross-section.

• Suitable for overlapping arrangements.

• Commonly used in continuous-span roofing systems.

• Widely used in large industrial buildings and PEB structures.

The selection between C and Z purlins depends on the building design, structural arrangement and project requirements.

Why Are Steel Purlins Important in Industrial Roofing?

Steel purlins play an essential role in modern industrial roofing systems. They provide the necessary support for roofing sheets and help transfer roof loads to the main structural framework.

Some important advantages include:

1. Structural Support: Purlins provide a supporting framework for roofing sheets and wall cladding systems.

2. Lightweight Construction: Steel purlins offer structural support without unnecessarily increasing the weight of secondary framing members.

3. Design Flexibility: Different purlin profiles allow engineers to select suitable sections for different building designs.

4. Installation Convenience: Roll-formed steel purlins are convenient to handle, transport and install.

5. Versatile Applications: They are used in warehouses, factories, commercial buildings, agricultural sheds and industrial facilities.

6. Durability: Galvanized steel purlins offer corrosion protection and are suitable for a wide range of building applications.

Applications of Purlins in Different Industries

Purlins are used across multiple sectors because of their versatility and importance in steel construction.

Industrial Warehouses: Purlins provide support for roofing sheets and cladding systems in large storage facilities.

Manufacturing Factories: They form an important part of factory roofing structures and industrial building frameworks.

Pre-Engineered Buildings: Purlins are essential secondary structural components in pre-engineered building systems.

Commercial Buildings: They are used in commercial sheds, workshops and other steel-framed structures.

Agricultural Buildings: Purlins support roofing systems in agricultural storage facilities and sheds.

Infrastructure Projects: They are used in suitable steel-framed structures and various infrastructure-related construction applications.

How to Choose the Right Type of Purlin?

Selecting the right purlin is important for achieving a reliable and efficient roofing structure. The selection should always be based on engineering requirements and the intended application.

Consider the following factors:

1. Building Design: Understand the overall structure and roofing arrangement before selecting a purlin profile.

2. Structural Requirements: Consider the expected loads and support conditions.

3. Purlin Profile: Select between C, Z, U, L, Hat or special sections according to the application.

4. Material Quality: Choose suitable steel material for the intended building environment.

5. Corrosion Protection: Consider the environmental conditions and required protection against corrosion.

6. Installation Requirements: Evaluate the fixing arrangement, connections and installation process.

7. Project Requirements: Follow approved structural drawings and engineering recommendations.

Geometric Steels – Your Purlin Manufacturing Partner

Geometric Steels Roll Forming Pvt. Ltd. manufactures a wide range of steel purlin sections for industrial, commercial and infrastructure applications.

With modern roll forming technology, Geometric Steels offers different purlin profiles to meet diverse construction requirements.

Our Purlin Product Range:

• C Purlins

• Z Purlins

• U Purlins

• L Purlins

• Hat Sections

• Special Section Purlins

Frequently Asked Questions About Purlins

1. What are the different types of purlins?

The commonly used types of purlins include C purlins, Z purlins, U purlins, L purlins, Hat purlins and special section purlins.

2. What is the main purpose of purlins?

Purlins support roofing sheets and transfer roof loads to the main structural framework of a building.

3. What is the difference between C purlins and Z purlins?

C purlins have a C-shaped cross-section, while Z purlins have a Z-shaped profile. Z purlins are particularly suitable for overlapping arrangements in continuous-span roofing systems.

4. Which type of purlin is commonly used in industrial buildings?

C and Z purlins are widely used in industrial buildings, warehouses and pre-engineered structures. The selection depends on the structural design and project requirements.

5. Are steel purlins suitable for warehouse construction?

Yes. Steel purlins are commonly used in warehouses to support roofing sheets and wall cladding systems.

6. What are galvanized steel purlins?

Galvanized steel purlins are steel sections protected with a zinc coating. This coating helps protect the steel against corrosion.

7. Can purlins be customized?

Yes. Purlins can be manufactured in different shapes and profiles to meet specific project and structural requirements, subject to manufacturing capabilities.

8. How do I select the right purlin for my project?

The selection depends on building design, structural requirements, roofing arrangement, loading conditions and engineering recommendations.

Conclusion

Purlins are essential components of modern steel construction. From C and Z purlins to U, L, Hat and special sections, each profile offers different characteristics and applications.

Understanding the different types of purlins helps architects, structural engineers, contractors and builders make informed decisions when planning industrial roofing and steel structures.

Selecting the appropriate purlin profile according to project requirements can contribute to a strong, efficient and reliable building structure.

View for more product

Stone Coated Roofing Sheets :- https://www.colourcoatedroofing.com/products/category/stone-coated-roof-tiles/1

Metal Louvers :- https://www.colourcoatedroofing.com/products/category/metal-louvers/1

Ridg vent :- https://www.colourcoatedroofing.com/products/category/ridge-vents/1

Need expert guidance for your industrial roofing project?

Submit your requirements through our product inquiry form, and our team will connect with you with the most suitable solution.

Purlin Product Inquiry 

                                                                                                Click For Enquiry