C & Z Purlins | Aditya Sales Corporation

Close-up of stacked C and Z purlin steel sections

QUICK PRODUCT SUMMARY

C & Z Purlins at a Glance

C and Z purlins are cold roll-formed from galvanized steel coil into structural sections that support roof sheeting and wall cladding, transferring load back to the primary rafters and columns of a building frame. They are supplied to precise lengths with pre-punched holes, reducing the need for on-site cutting, drilling or welding.

Construction

Cold roll-formed galvanized structural steel

Profiles

C-section and Z-section

Applications

PEB, industrial and commercial structures

Available configurations: C Purlins • Z Purlins • Eave Struts • Girts • Bridging and Cleats

PERFORMANCE ADVANTAGES

Why C & Z Purlins Are Specified

Cold-formed purlins are selected for projects that need a practical balance of strength, low weight and fast, accurate erection. Actual load capacity always depends on the selected section, thickness, span and design loading.

High Strength-to-Weight Ratio

The cold-forming process increases material strength at the bends, allowing purlins to carry structural loads while remaining relatively lightweight.

Corrosion-Resistant Coating

Galvanized coating helps protect the steel section from corrosion, supporting a longer service life across varied site conditions.

Precise Factory Fabrication

Sections are cut to length and pre-punched at the factory, reducing on-site cutting, drilling and welding requirements.

Longer Spans, Fewer Columns

Z purlins can be lapped over supports, which can help increase load capacity and allow longer spans between columns in suitable designs.

Faster Erection

Bolted connections and factory-finished sections allow faster, more predictable erection compared with fabricated hot-rolled members.

Design Flexibility

Available across multiple depths, thicknesses and yield grades, allowing the section to be matched to the specific span and loading requirement.

APPLICATION AREAS

Where C & Z Purlins Are Used

C and Z purlins form the secondary framing in a wide range of steel-framed structures, supporting roof sheeting, wall cladding and mounted equipment.

Z purlins installed in a PEB warehouse steel frame

PEB Structures

Warehouses and Industrial Sheds

Z purlins are widely used as roof framing in pre-engineered buildings, warehouses and industrial sheds, supporting the roof sheeting between rafters.

C and Z purlins being installed on a roof frame

Roofing

Roof and Wall Framing

C and Z sections support roof sheets and wall cladding panels, transferring wind and gravity loads back to the main structural frame.

Commercial

Cold Storage and Commercial Buildings

Used across cold storage facilities, commercial buildings and showrooms wherever a steel-framed roof and wall structure is specified.

C purlins used in a solar mounting structure

Renewable Energy

Solar Mounting Structures

Suitable purlin sections are also used within solar panel mounting structures and supporting steel framework, subject to project design.

PRODUCT CONFIGURATIONS

Choose the Right Purlin Configuration

The profile, depth and thickness should be selected according to the span, spacing, roof pitch and design loading confirmed by the structural engineer.

C Purlins

A C-shaped open section commonly used for wall girts, shorter spans and applications where sections are not required to overlap at supports.

Z Purlins

A Z-shaped section that allows lapping over intermediate supports, commonly used for roof purlins on longer spans in PEB structures.

Eave Struts

A specially formed section used at the eave of the building, where the roof and wall framing systems meet.

Girts

Horizontal wall framing members that support wall cladding and transfer wind loads back to the primary columns.

Bridging and Sag Rods

Accessories used between purlins to restrain the section and improve overall structural performance under load.

Cleats and Brackets

Connection components used to bolt purlins and girts to the primary rafters, columns and end frames.

Note: final section, thickness and spacing must be confirmed against the project's structural design and applicable design code.

PROFILE SELECTION

C Purlin or Z Purlin — What's the Difference?

C and Z sections serve the same general purpose but behave differently at supports. The choice between them depends on the span, the roof layout and whether the design takes advantage of overlapping sections at intermediate supports.

Z purlins can be lapped over intermediate supports, which effectively doubles the cross-sectional area at that point and can increase load capacity on longer spans.
C purlins are commonly used for wall girts and applications without lapping, since their shape does not nest for overlap in the same way.
Z purlins are the more common choice for roof framing in typical PEB structures because continuous, lapped spans generally perform better under load than simply supported spans.
Final selection should always follow the structural engineer's design, calculated against the applicable design code, and the project drawings.

Technical note: Purlin design in India is commonly checked against IS 801 (working-stress design of cold-formed sections), where the listed section dimensions in IS 811 are gross properties — actual load capacity is calculated from effective, reduced properties. Section capacity, yield strength and design span figures should only be quoted when supported by the manufacturer's tested section properties and the project's structural design. Please request the current technical datasheet and consult your structural engineer for figures applicable to your project.

PRODUCT SELECTION

How to Select the Right Purlin Size

The correct depth, thickness and grade cannot be chosen from a general chart alone. It should be based on the span, spacing, roof pitch, wind and load conditions confirmed by structural design.

Factors That Influence Selection

Span between primary rafters or columns
Purlin spacing across the roof or wall
Roof pitch and building geometry
Wind, snow and live load conditions
Sheeting or cladding weight
Lapping requirement at supports
Required yield strength and coating
Applicable design code and standard

Information We Need for a Recommendation

Building type and overall dimensions
Bay spacing and roof pitch
New or existing structure
Applicable design loads, if available
Preferred profile, if already specified
Roofing or cladding material
Structural drawings, if available
City and project location

PRODUCT COMPARISON

C Purlin vs Z Purlin vs Sigma Purlin

Each cold-formed profile behaves differently at supports and under load. The right choice depends on the span, lapping requirement, design code and overall structural design.

Factor	C Purlin	Z Purlin	Sigma Purlin
Section shape	Open C-shaped channel	Open Z-shaped section with sloped flanges	Sigma-shaped section, a variant of the Z profile
Lapping at supports	Not typically designed to lap	Can be lapped over intermediate supports	Can be lapped, similar to Z sections
Common use	Wall girts and shorter-span applications	Roof purlins on longer PEB spans	Roof and wall framing as an alternative to Z sections
Nesting for transport	Nests less efficiently than Z or Sigma	Nests reasonably well for transport	Generally nests efficiently, reducing transport volume
Selection basis	Span, wall framing requirement	Span, lapping requirement, roof design	Manufacturer availability and structural design

No single profile is universally best for every application. Selection should be based on the complete structural design rather than section type alone.

MANUFACTURING AND QUALITY

Manufactured for Structural Project Requirements

Coil quality, roll-forming accuracy, punching precision and dimensional control all influence how purlins perform and fit together on site.

Steel Coil Selection

Galvanized steel coil is selected to match the required yield strength and coating grade for the project.

Roll-Forming Accuracy

Sections are cold roll-formed under controlled conditions to maintain consistent depth, flange and lip dimensions.

Precision Punching

Bolt holes are pre-punched to the project's connection design, supporting accurate, faster on-site assembly.

Inspection and Dispatch

Length, straightness and dimensional inspection support consistent quality before packing and dispatch.

TECHNICAL INFORMATION

C & Z Purlin Specifications

The exact specification varies by profile, depth, thickness and grade. Refer to the current technical datasheet and structural design for final project selection.

Material	Cold roll-formed galvanized structural steel
Profile	C-section and Z-section
Section depth	Typically 100mm–300mm for Z sections and 50mm–350mm for C sections across the Indian market; exact range depends on manufacturer
Thickness	Typically 1.5mm–3.15mm; refer to current product datasheet for exact availability
Yield strength	Standard grade around 240 MPa and high-tensile grade around 350 MPa are common; refer to current product datasheet
Coating	Galvanized coating, commonly specified in the Z120–Z275 GSM range; refer to current product datasheet
Length	Supplied to project-specific lengths
Hole punching	Pre-punched as per project connection design
Applicable standards	Commonly referenced against IS 801 (design), IS 811 (section dimensions) and IS 10748 (steel raw material); confirm exact applicable standard from the current datasheet
Typical applications	PEB roofs, walls, girts and secondary framing
Installation method	Bolted connection to primary structural frame