Curved Metal
Sheeting
Radius-curved corrugated, Trimdek®, Hi-Ten®, Klip-Lok® and Spandek® sheeting in 0.6 BMT G300 COLORBOND® steel, Zincalume® and Galvanised. Curved on purpose-built roll-curving machines to your specified radius — concave or convex. Ideal for barrel vault roofs, curved canopies, architectural feature facades and curved wall cladding. Custom radii and special profiles available on enquiry.
The Process
How Curving Works
01
Specify Your Radius
Provide the required curve radius (in mm), profile type, material, BMT, cover width and sheet length. Your engineer or architect can confirm the minimum radius for your specific profile and span.
02
Roll Curving
Sheets are passed through a purpose-built 3-roll curving machine. The rolls are set to your specified radius. Corrugated profiles can achieve tighter radii than ribbed or concealed-fix profiles.
03
Quality Check
Each curved sheet is checked against the specified radius using a radius gauge. Sheets outside tolerance are re-curved or rejected. COLORBOND® coating integrity is maintained throughout the curving process.
04
Cut to Length & Deliver
Curved sheets are cut to your specified length (up to 12,000 mm) and delivered flat-packed on purpose-built curved sheet stillages to prevent distortion in transit.
Product Catalogue
Browse All Profiles
Click any section to expand and view full specifications. Add individual SKUs or entire sections to your enquiry.
E-E-A-T Technical Reference
Curved Sheeting Specifications
Material grades, minimum radius guidance, structural considerations, applicable standards and design notes for radius-curved metal sheeting.
Minimum Radius Guide by Profile
| Profile | BMT | Min Concave Radius | Min Convex Radius | Notes |
|---|---|---|---|---|
| Corrugated 762 | 0.6 BMT G300 | 600 mm | 600 mm | Tightest radius of all profiles; suitable for tight barrel vaults and heritage restorations |
| Trimdek® / Hi-Ten® | 0.6 BMT G300 | 1,500 mm | 1,500 mm | Wider rib spacing requires larger minimum radius than corrugated |
| Klip-Lok® 700 | 0.6 BMT G300 | Not recommended | 3,000 mm | Concealed fix; convex (barrel) curve only; concave not recommended |
| Spandek® | 0.6 BMT G300 | On application | 1,200 mm | Low 18mm rib; suited to curved wall cladding and fascias |
| Custom / Other | 0.6 BMT G300 (std) | Enquire | Enquire | Profile-dependent; confirm with Steel Source Australia before specifying |
* Minimum radii are indicative. Actual minimum radius depends on material temper, coil set and curving machine setup. Confirm with Steel Source Australia before specifying.
Concave Curve
Curve faces upward (hollow side up)
The sheet curves inward — like the inside of a bowl. Used for curved roofs where rainwater drains toward the centre. Also called a "valley curve". Corrugated profiles can achieve tighter concave radii than ribbed profiles.
Convex Curve
Curve faces downward (dome side up)
The sheet curves outward — like the outside of a dome. Used for barrel vault roofs and curved canopies where rainwater drains to the edges. Also called a "barrel curve". Most profiles can achieve convex curves.
Radius
Distance from curve centre to sheet surface
Measured in millimetres. A smaller radius = a tighter curve. A larger radius = a gentler curve. The minimum achievable radius depends on the profile geometry, material and BMT. Always confirm minimum radius before specifying.
BMT (Base Metal Thickness)
Thickness of the steel substrate
Measured in millimetres, excluding the metallic coating and paint. Standard BMT for curved sheeting is 0.6 mm (G300 steel) — this gauge provides the stiffness needed to hold a consistent radius without oil-canning or spring-back. Lighter gauges (0.42, 0.48) are not recommended for curved work as they are prone to distortion.
COLORBOND® Steel
BlueScope® pre-painted steel substrate
COLORBOND® steel is a pre-painted, metallic-coated steel manufactured by BlueScope® Steel. The paint system is a thermoset polyester applied before curving. The curving process does not damage the COLORBOND® coating when performed within the minimum radius limits.
Structural Considerations
Curved sheets have different span tables
Curved sheets behave differently to flat sheets under load. The span tables for flat sheeting do not apply to curved profiles. An engineer must confirm purlin/girt spacing, fixing requirements and structural adequacy for curved roof applications.
Applicable Standards
AS 1562.1:2018
Design and installation of sheet roof and wall cladding — Metal
Primary standard for the design and installation of metal roof and wall cladding in Australia. Covers fixing requirements, laps, penetrations and curved applications.
AS/NZS 4600:2018
Cold-formed steel structures
Covers the structural design of cold-formed steel members including curved sheeting used as structural diaphragms or stressed-skin elements.
AS/NZS 1170.2:2021
Structural design actions — Wind actions
Wind load standard used to determine design wind pressures on curved roof surfaces. Curved roofs have different pressure coefficients to flat roofs.
BlueScope COLORBOND® Technical Manual
Design and installation guide for COLORBOND® steel
BlueScope's technical manual covers minimum bend radii, fixing requirements, thermal movement, and curved roof design guidance for COLORBOND® steel products.
NCC 2022 Volume One
National Construction Code — Class 2–9 Buildings
Sets weatherproofing performance requirements for curved roof and wall cladding on commercial and industrial buildings.
AS/NZS 2312.2:2014
Guide to the protection of structural steel against atmospheric corrosion — Hot-dip galvanizing
Used to determine appropriate material selection (COLORBOND®, Zincalume® or Galvanised) based on corrosivity classification of the project environment.
Get a Quote
Need a Custom Radius?
Provide your profile type, material, BMT, required radius and sheet length. We'll confirm feasibility and lead time. Add profiles to your enquiry above or contact us directly.