Custom Orb corrugated roofing
Custom Orb is Lysaght's 16 mm corrugated steel roofing profile: 762 mm cover, 5 degree minimum pitch. The heritage AU default for federation roofs.
Ask Chalkline about this →Custom Orb is Lysaght’s brand name for traditional corrugated steel roofing, the heritage default profile across Australian residential building. The rounded corrugations sit on a 76 mm pitch with a 16 mm nominal rib height in the COLORBOND-finished Custom Orb (17 mm in the galvanised Custom Blue Orb variant). Effective cover width is 762 mm. Minimum roof slope is 5 degrees (verified 2026-05-16, Lysaght Custom Orb profile page).
Specifications
| Item | Custom Orb | Custom Blue Orb |
|---|---|---|
| Rib height | 16 mm nominal | 17 mm nominal |
| Cover width | 762 mm | 762 mm |
| Minimum pitch | 5 degrees (1 in 12) | 5 degrees |
| Material | COLORBOND-finished steel | Hot-dip galvanised steel |
| Common BMT | 0.42 mm, 0.48 mm | 0.48 mm, 0.60 mm |
| Side lap | 1.5 corrugations | 1.5 corrugations |
| Fixing | Pierce-fix into rib crests with hex screw + EPDM washer | Same |
Where it’s used
- Federation and heritage homes: the visual default; a Trimdek roof on a federation house is jarring.
- Roof replacements on existing corrugated roofs: matching the original profile.
- Verandahs and outbuildings: traditional aesthetic, cheaper than premium profiles.
- Class 1a residential where the client’s design preference is the traditional look.
Why it has lost market share to Trimdek
Custom Orb dominated Australian roofs for a century but has been displaced for most new builds:
- Minimum pitch is 5 degrees versus 2 degrees for Trimdek. Modern low-pitch architecture pushes the design under Custom Orb’s threshold.
- Below 5 degrees water tracks back along the rounded valley of the corrugation against the lap and leaks through. The anti-capillary geometry of square-rib profiles doesn’t exist on Custom Orb.
- Aesthetic preference has shifted toward the cleaner contemporary look of square-rib profiles in new builds.
- Wider profiles cover faster: Custom Orb 762 mm versus 700-900 mm options on newer profiles.
Custom Orb remains specified for heritage matching and federation revival builds.
On-site checks
- Fasteners through every second corrugation rib at supports (typical pattern; check the Lysaght install guide for the specific BMT).
- 1.5 corrugation side lap with the upper sheet’s lap-side oriented away from prevailing wind.
- Driven to EPDM washer compression (just below the flange bend); over- and under-driven both leak.
- Roof pitch confirmed 5 degrees or steeper. Below 5 degrees switch profile, do not install Custom Orb.
Also known as: CUSTOM ORB, Lysaght Custom Orb, corrugated iron, corrugated roofing.
Category: Metal roofing / cladding profiles.
Related
See also
Last updated: 2026-05-16. Verified: 2026-05-16.