Z Purlin: Sizes, Weight Chart, Prices & Specifications for Industrial Buildings

Z Purlin: Sizes, Weight Chart, Prices & Specifications for Industrial Buildings<\/h2>

Z purlins (also written zee purlins or zed purlins) are cold-formed steel secondary members that support roof sheets and wall cladding in warehouses, factories, and pre-engineered buildings. Their Z-shaped cross-section overlaps at the joints, which makes them stronger and more splice-friendly than C purlins of the same weight. This page is the complete buying reference from Sino East Steel Group — a direct steel structure manufacturer in Tianjin, China: Z purlin sizes and weight charts, material and galvanizing options, 2026 price ranges, and the exact way to order Z purlins for your project.

1. What Is a Z Purlin?

A Z purlin is a cold-rolled, Z-section steel member used as secondary framing. The purlin sits between the primary frame (rafters and columns) and the roof or wall panel, transferring wind and roof loads into the main structure. The Z profile’s key advantage is lapping: purlins are nested and overlapped over the support point, so longer continuous spans are achieved with lighter sections than a C purlin would need.

Z purlins are manufactured by cold roll forming from galvanized or cold-rolled steel strip, then punched with oval holes to accept M12/M16 bolts and other fixing hardware. They are produced to international standards including EN 10162, JIS G 3350, ASTM A1003, and GB/T 6723 (cold-formed steel sections).

2. Z Purlin vs C Purlin: Which One Do You Need?

Comparison	Z Purlin (Z Section)	C Purlin (C Section)
Cross-section	Z-shaped, symmetrical flanges	C/U-shaped with parallel flanges
Joint method	Lapping/overlapping at supports — continuous spans	Butt joints with splice plates
Strength	Higher for the same weight; better for long spans	Good, but more material needed at long spans
Best for	Roof purlins on buildings over 20 m wide; multi-span layouts	Wall girts, short spans, small buildings
Installation	Nested stacking for shipping; simple bolted laps	Simple end-to-end fixing
Typical use	Warehouses, factories, PEB roofs	Girts, mezzanines, small workshops

For most industrial roofs, Z purlins are the cost-efficient choice. See our C purlin page for the alternative profile, and compare both against your engineer’s load calculations before ordering.

3. Z Purlin Sizes & Dimensions

Standard Z purlin sizes cover section depths from 100 mm to 300 mm. The table below lists common profiles with their flange and lip dimensions. Custom sizes and lengths are produced to order.

Section (mm)	Depth × Flange × Lip	Typical Thickness	Common Lengths
Z100	100 × 50 × 20	1.5–2.0 mm	6 / 9 / 12 m
Z120	120 × 50 × 20	1.5–2.0 mm	6 / 9 / 12 m
Z140	140 × 50 × 20	1.5–2.5 mm	6 / 9 / 12 m
Z150	150 × 60 × 20	1.8–2.5 mm	6 / 9 / 12 m
Z160	160 × 60 × 20	1.8–2.5 mm	6 / 9 / 12 m
Z180	180 × 70 × 20	2.0–3.0 mm	6 / 9 / 12 m
Z200	200 × 70 × 20	2.0–3.0 mm	6 / 9 / 12 m
Z220	220 × 75 × 20	2.0–3.0 mm	6 / 9 / 12 m
Z250	250 × 75 × 20	2.5–3.0 mm	6 / 9 / 12 m
Z300	300 × 80 × 25	2.5–3.0 mm	6 / 9 / 12 m

Dimension tolerances follow EN 10162 and GB/T 6723. For a size not listed, send your drawing — our roll forming line adjusts to custom profiles with a short tooling lead time.

4. Z Purlin Weight Chart (kg per metre)

Indicative weights for common galvanized Z purlin sections (calculated per GB/T 6723, ±5%):

Section	1.5 mm	1.8 mm	2.0 mm	2.5 mm	3.0 mm
Z140 × 50 × 20	3.3 kg/m	3.9 kg/m	4.3 kg/m	5.4 kg/m	—
Z160 × 60 × 20	3.6 kg/m	4.3 kg/m	4.8 kg/m	6.0 kg/m	—
Z180 × 70 × 20	—	4.7 kg/m	5.2 kg/m	6.5 kg/m	7.8 kg/m
Z200 × 70 × 20	—	5.1 kg/m	5.6 kg/m	7.0 kg/m	8.4 kg/m
Z220 × 75 × 20	—	—	6.0 kg/m	7.5 kg/m	9.0 kg/m
Z250 × 75 × 20	—	—	6.6 kg/m	8.2 kg/m	9.9 kg/m
Z300 × 80 × 25	—	—	—	9.9 kg/m	11.9 kg/m

Use the weight chart to estimate freight: a 40 ft container holds roughly 22–25 tonnes of nested Z purlins, which typically covers 1,500–2,500 m of sections depending on profile.

5. Material Grades & Corrosion Protection

Option	Specification	Best For
Structural steel	Q235B / S235JR — yield 235 MPa	Dry internal environments
High-strength steel	Q355B / S355JR / S450–S550 (cold forming)	Long spans, heavy loads
Galvanized (pre-painted coil)	Z180 / Z275 / Z350 / Z450 g/m² per EN 10346	Corrosive atmospheres, coastal sites
Hot-dip galvanized (after forming)	HDG 70–85 µm (ISO 1461)	Aggressive coastal / industrial exposure
Paint coating	Polyester / PVDF topcoat, optional	Architectural color matching

For warehouse and factory projects in humid or coastal regions — including much of Africa, the Middle East, and Southeast Asia — specify at least Z275 galvanizing. Our mill test certificates (EN 10204 3.1) accompany every batch.

6. Z Purlin Prices in 2026 (FOB China)

Indicative export pricing from our Tianjin factory (FOB, 2026):

Product	Indicative Price	MOQ
Galvanized Z purlin (Z275, standard sections)	USD 780–980 per tonne FOB	5 tonnes (mix sizes OK)
High-strength / thick sections (2.5–3.0 mm)	USD 820–1,050 per tonne FOB	5 tonnes
Hot-dip galvanized Z purlin (HDG)	USD 950–1,200 per tonne FOB	10 tonnes
Punching / custom length / drilling	Included or nominal charge	—

Prices move with global steel coil markets and exchange rates, so treat these as planning ranges. For a firm quotation send your sections, quantities, and destination port to paul@sinoeaststeel.com. To estimate the full landed cost of a steel building in your market, see our Kenya, Nigeria, and UAE cost guides.

7. Z Purlin Applications

• Roof purlins — spanning between rafters in warehouses, factories, and distribution centers; typical spacing 1.2–1.5 m.
• Wall girts — horizontal members supporting wall cladding and composite panels.
• Pre-engineered buildings (PEB) — standard secondary framing for clear-span structures.
• Canopies, mezzanines, and equipment platforms — lighter-duty Z sections.
• Agriculture and cold storage — galvanized Z purlins withstand humidity in poultry, dairy, and cold-chain buildings.

For the full range of steel structure products we manufacture — PEB, warehouses, and heavy steel — start from our product catalogue.

8. Why Buy Z Purlins Direct from Sino East Steel Group

Sino East Steel Group is a direct China steel structure manufacturer, not a trader. Since 1993 we have operated a 50,000 m² fabrication facility in Tianjin Industrial Park, Daqiuzhuang — China’s largest steel processing hub — with our own cold roll forming lines, CNC punching, and hot-dip galvanizing capacity.

• Factory-direct pricing — no middleman; 20–40% below regional re-seller prices.
• Certified quality — ISO 9001:2015, ISO 3834-2, EN 1090 EXC3/EXC4, AWS D1.1; mill test certificates on every batch.
• Custom profiles and punching — holes, slots, and lengths to your shop drawings.
• Export documentation — invoice, packing list, certificate of origin, EN 10204 3.1 certificates for smooth clearance.
• 100,000+ tonnes annual capacity — standard sections ship in 1–2 weeks; custom profiles in 3–4 weeks.

Before committing to any factory, use our manufacturer verification checklist — we welcome third-party inspection at any stage.

9. How to Order Z Purlins from China

1. Send your section size (or drawing), length, quantity, and destination port.
2. Receive an itemized quotation within 24–48 hours (FOB/CIF).
3. Approve the shop drawing and punching pattern.
4. We fabricate and test (SGS/BV/TÜV inspection optional).
5. We ship FCL from Tianjin with full export documentation.

For complete projects — purlins plus primary steel — see our procurement guide for importers.

10. Z Purlin Span & Spacing Guide

Span and spacing depend on section size, steel grade, and local wind/snow loads — always confirm with structural calculations. As a planning reference for roof purlins with 1.2–1.5 m spacing and light cladding:

Section	Typical Single Span	Typical Continuous (lapped) Span
Z140 × 50 × 20 × 2.0	3.5–4.5 m	5.0–6.0 m
Z160 × 60 × 20 × 2.0	4.0–5.0 m	5.5–6.5 m
Z200 × 70 × 20 × 2.0	4.5–5.5 m	6.0–7.5 m
Z250 × 75 × 20 × 2.5	5.5–6.5 m	7.5–9.0 m
Z300 × 80 × 25 × 3.0	6.5–8.0 m	9.0–11.0 m

Lapping over supports is what makes Z purlins economical for wide buildings: a continuous two-span purlin carries roughly 25–30% more load than the same section used as a single span. Our engineers can produce a full purlin schedule and connection detail for your frame free of charge when you request a quotation.

11. Packing, Shipping & Delivery

Z purlins are stacked and nested into compact bundles, strapped with steel bands, and loaded into 40 ft containers or break-bulk holds at Tianjin Port. Each bundle carries a mark tag with your project name, section, and length for easy site sorting. Standard export documentation — commercial invoice, packing list, bill of lading, certificate of origin, and EN 10204 3.1 mill test certificates — is provided with every shipment.

Typical transit times: 3–4 weeks to the Middle East (Jebel Ali), 4–6 weeks to East and West Africa (Mombasa, Lagos), 4–5 weeks to Europe, and 3–5 weeks to North America. For full-project shipping details, read our international shipping and installation guide.

12. Z Purlin FAQ

Q: What is the difference between a Z purlin and a C purlin?
A: The Z section laps and nests at supports, giving longer continuous spans and higher strength per kilogram; the C section is butt-jointed and is usually used for wall girts and shorter spans.

Q: What sizes do Z purlins come in?
A: Standard depths range from 100 mm to 300 mm with flange widths of 50–80 mm, in thicknesses from 1.5 mm to 3.0 mm, and lengths up to 12 m (custom lengths available).

Q: How much does a Z purlin cost?
A: In 2026, galvanized Z purlins run roughly USD 780–980 per tonne FOB China; hot-dip galvanized sections USD 950–1,200 per tonne. Freight and duty vary by destination.

Q: What is the weight of a Z purlin per metre?
A: For example, a Z200×70×20×2.0 mm section weighs about 5.6 kg/m; a Z250×75×20×2.5 mm section about 8.2 kg/m. Use our weight chart above for planning.

Q: Are Z purlins galvanized?
A: Yes — we supply Z180 to Z450 galvanized purlins per EN 10346, or fully hot-dip galvanized (HDG 70–85 µm) sections for coastal and aggressive environments.

Q: What is the standard for Z purlins?
A: Common standards are EN 10162, JIS G 3350, ASTM A1003, and GB/T 6723. Our production and tolerances comply with all four.

Q: Can you make custom Z purlin profiles?
A: Yes. Our roll forming line produces custom depths, flange widths, lips, holes, and lengths to your shop drawings, with 3–4 weeks tooling and production lead time.

Q: What is the recommended purlin spacing for Z purlins?
A: For roof purlins with light cladding (0.5 mm sheet or sandwich panel), the standard spacing is 1.2–1.5 m; heavier or insulated panels may require 1.0–1.2 m. Wall girt spacing is typically 1.2–1.5 m depending on panel spanning capacity and wind zone.

Q: How do I get a Z purlin quotation?
A: Email your section size, length, quantity, and destination port to paul@sinoeaststeel.com or message us on WhatsApp — you will receive an itemized FOB/CIF quotation within 48 hours.