Repair Systems — 04 — Roofing Defects
Colorbond corrugated sheet replacement systems
Colorbond corrugated steel sheet (sold as Custom Orb by Lysaght and equivalent by Stramit and Stratco) is the most widely used metal roofing product in Australia, specified on both residential and Class 2 strata buildings for its durability, colour range and familiar sinusoidal profile. Sheet replacement requires matching the existing profile, pitch and fixing system and selecting a Colorbond colour consistent with the original or an approved variation under any applicable strata by-law or heritage requirement.
What is Colorbond corrugated sheet replacement?
Colorbond corrugated steel sheet (sold as Custom Orb by Lysaght and equivalent by Stramit and Stratco) is the most widely used metal roofing product in Australia, specified on both residential and Class 2 strata buildings for its durability, colour range and familiar sinusoidal profile. Sheet replacement requires matching the existing profile, pitch and fixing system and selecting a Colorbond colour consistent with the original or an approved variation under any applicable strata by-law or heritage requirement.
Technical Reference
BMT selection, fixing systems, lap requirements, and colour matching guidance
Product Reference
3 products — 3 brands — corrugated Colorbond steel sheet systems — scroll to view all
Lysaght Custom Orb
Corrugated Colorbond steel sheet — 762mm cover — AS 1562.1
System Description
Custom Orb is Lysaght's corrugated sheet product made from BlueScope Colorbond steel with a 76mm corrugation pitch and 762mm nominal cover width. 0.42mm BMT is the standard residential gauge; 0.48mm is specified for Class 2 and commercial applications for improved uplift resistance. Available in the full Colorbond colour range with a 25-year BlueScope warranty against perforation by corrosion. Fixing is typically by Class 3 hex-head self-drilling screws through the crown of each corrugation into steel purlins, or by Class 4 screws where C3 corrosivity or higher is specified. End laps minimum 150mm for pitches ≥5°, minimum 300mm for pitches <5°. Side laps minimum one corrugation. Sheet length is project-specific — confirm availability with Lysaght branch before ordering. Confirm colour consistency across different production batches when ordering replacement sheets — significant colour variation can occur between batches. The product is available through Lysaght branches nationally and is the benchmark corrugated Colorbond sheet product against which Stramit and Stratco equivalents are assessed. TODO: owner confirm current Custom Orb gauge range and availability in your market before specifying.
Technical Properties
- Colorbond steel substrate — BlueScope steel with Activate technology zinc-aluminium-magnesium alloy coating
- 0.42mm and 0.48mm BMT — residential and commercial gauges; confirm gauge with AS 1562.1 and project engineer for uplift requirements
- 76mm corrugation pitch, 762mm cover width — standard sinusoidal profile compatible with existing Custom Orb profiles
Limitations
- Colour matching: Colorbond colours fade over time — replacement sheets from current production will not match weathered existing sheets. Advise client of likely colour variation before ordering.
- End lap sealant: End laps must be sealed with butyl tape or equivalent — unsealed end laps are a common source of metal roof leaks. Confirm sealant compatibility with Colorbond coating.
- Gauge selection: 0.42mm BMT may not be sufficient for high-wind-zone or Class 2 buildings — confirm gauge and fixing pattern with structural engineer for wind uplift.
PROCUREMENT SOURCES
Lysaght branches nationally, BlueScope Steel distributors, Stratco (reseller), Tradelink, specialised roofing sheet suppliers
Confirm suitability with the current manufacturer TDS before specifying or applying.
Stramit Corrugated Colorbond Sheet
Corrugated Colorbond steel sheet — equivalent to Custom Orb — AS 1562.1
System Description
Stramit corrugated Colorbond sheet is manufactured from BlueScope Colorbond steel to the same standard sinusoidal corrugated profile (76mm pitch, 762mm cover) as Lysaght Custom Orb. The two products are dimensionally interchangeable in the same roof installation. Available in 0.42mm and 0.48mm BMT and the full current Colorbond colour range. Stramit is a major national roofing sheet supplier with branches in most states — availability may vary by location. Fixing system (Class 3/4 hex-head screws, end lap and side lap requirements) is identical to Custom Orb. Selection between Stramit and Lysaght is typically driven by local branch availability, lead time, and price rather than any technical difference in the product. Confirm colour batch consistency with the local Stramit branch when ordering replacement sheets for an existing roof — as with Custom Orb, colour variation between production batches is a known issue. TODO: owner confirm Stramit corrugated is available in your state/territory before specifying — product ranges and availability vary by branch.
Technical Properties
- Same BlueScope Colorbond steel substrate and Activate technology coating as Lysaght Custom Orb
- Profile dimensionally interchangeable with Custom Orb — 76mm pitch, 762mm cover width
- Same fixing system as Custom Orb — Class 3/4 hex-head self-drilling screws, same end lap and side lap requirements
Limitations
- Colour matching: same caveats as Lysaght Custom Orb — weathered existing sheets will not match current production colour. Advise client before ordering.
- Confirm local branch availability before specifying — Stramit branch coverage varies by state and territory.
- Batch colour variation: order all replacement sheets in a single batch where possible.
PROCUREMENT SOURCES
Stramit branches nationally, Tradelink, roofing sheet specialists
Confirm suitability with the current manufacturer TDS before specifying or applying.
Stratco Corrugated Colorbond Sheet
Corrugated Colorbond steel sheet — 762mm cover — retail and trade supply
System Description
Stratco corrugated Colorbond sheet is a retail and trade-supply equivalent to Lysaght Custom Orb and Stramit corrugated, manufactured from BlueScope Colorbond steel to the same standard 76mm-pitch sinusoidal profile. Available in Stratco stores nationally — Stratco's wide retail network makes it a practical source for smaller replacement orders where a full Lysaght or Stramit branch order is not practical. 0.42mm BMT is the standard availability; 0.48mm may not be available through Stratco retail — confirm before specifying for commercial applications. TODO: owner confirm current gauge and colour availability at your local Stratco store before ordering.
Technical Properties
- Standard corrugated profile — 76mm pitch, 762mm cover width — dimensionally equivalent to Lysaght Custom Orb and Stramit corrugated
- BlueScope Colorbond steel substrate — Activate technology zinc-aluminium-magnesium alloy coating
- 0.42mm BMT standard availability through Stratco stores — confirm 0.48mm BMT before specifying for commercial use
Limitations
- 0.48mm BMT availability uncertain through Stratco retail — confirm before specifying for Class 2 or commercial applications.
- Confirm gauge and colour availability at local Stratco store before ordering — retail stock varies by location.
- Same colour-matching caveats as Custom Orb and Stramit — weathered existing sheets will not match current production colour.
PROCUREMENT SOURCES
Stratco stores nationally (retail and trade)
Confirm suitability with the current manufacturer TDS before specifying or applying.
Brand Equivalence
All three products share the same corrugated profile and BlueScope Colorbond substrate. Selection is driven by supply channel and local availability.
| Product A | Product B | Equivalence note |
|---|---|---|
| Lysaght Custom Orb | Stramit Corrugated | Dimensionally interchangeable — same 76mm pitch, 762mm cover, same BlueScope Colorbond substrate. Selection driven by local branch availability and price. |
| Stratco Corrugated | Custom Orb / Stramit | Same profile — wider retail availability for smaller orders; confirm 0.48mm BMT availability before specifying. |
| All three | — | Confirm colour batch consistency for replacement works — order all sheets in a single batch where possible. |
System Comparison
Side-by-side comparison of corrugated Colorbond sheet products. Confirm all selections against the current manufacturer TDS before specifying.
| Attribute | Lysaght Custom Orb | Stramit Corrugated | Stratco Corrugated |
|---|---|---|---|
| BMT range | 0.42mm, 0.48mm | 0.42mm, 0.48mm | 0.42mm (0.48mm — confirm) |
| Cover width | 762mm | 762mm | 762mm |
| Profile | 76mm pitch sinusoidal | 76mm pitch sinusoidal | 76mm pitch sinusoidal |
| Supply channel | Trade branches — national | Trade branches — national | Retail + trade stores — national |
Do not confuse Colorbond corrugated sheet with:
- Trimdek (high-rib trapezoidal) — a different profile with a trapezoidal rib, different fixing system, and different span/loading tables. Not interchangeable with corrugated sheet.
- Klip-Lok (concealed fix) — completely different fixing mechanism using a concealed clip system, no through-fasteners in the field. Not interchangeable with corrugated sheet and requires a different substructure and installer competency.
- Zincalume corrugated — the same standard sinusoidal corrugated profile (76mm pitch, 762mm cover) but with an unpainted zinc-aluminium alloy substrate rather than a Colorbond painted finish. Not a like-for-like substitute where a painted finish is required.
- Uncoated galvanised iron (GI) sheet — older legacy corrugated product with a hot-dipped galvanised zinc coating, no paint finish. No longer used in new or replacement works in Australia. Do not specify or accept GI sheet as a replacement for Colorbond.
Disclaimer
This page provides general technical information only. Final product selection must be confirmed against the current manufacturer technical data sheet, project specification, substrate condition, roof pitch, wind classification, AS 1562.1 requirements, structural engineer sign-off, and installer warranty conditions. Do not rely on this reference as a substitute for professional engineering or roofing consultant advice. All items marked TODO must be verified by the site owner before this page is published.