Minimum Roof Pitch for Colorbond: Custom Orb, Trimdek & Klip-Lok
Colorbond is the steel; the profile decides the minimum pitch. Lysaght lists 5° for Custom Orb corrugated, 2° for Trimdek and 1° for Klip-Lok 700 Hi-Strength in 0.48 BMT, which is why low skillion roofs are usually Trimdek or Klip-Lok.
Minimum pitch by system
| Roofing system | Minimum pitch | Conditions | Source |
|---|---|---|---|
| Custom Orb (corrugated, 762 mm cover) | 5° (1.05/12) | — | Lysaght |
| Trimdek (trapezoidal, 762 mm cover) | 2° (0.42/12) | — | Lysaght |
| Klip-Lok 700 Hi-Strength 0.48 BMT (700 mm cover) | 1° (0.21/12) | — | Lysaght |
| Klip-Lok 700 Hi-Strength 0.42 BMT (700 mm cover) | 2° (0.42/12) | Down to 1° only on certain commercial roofs with design provisions | Lysaght |
Choosing a profile for a low-pitch roof
Below 5° Custom Orb is out, so skillion roofs, patios and extensions at 2°–5° are usually Trimdek. At 1°–2°, a concealed-fix profile such as Klip-Lok is the standard choice because there are no fasteners through the pans.
At very low pitches, run length and gutter capacity matter as much as the profile. Check the manufacturer guide for maximum roof run, end laps and flashing details.
Frequently asked questions
What is the minimum roof pitch for colorbond steel?
Colorbond is the steel; the profile decides the minimum pitch. Lysaght lists 5° for Custom Orb corrugated, 2° for Trimdek and 1° for Klip-Lok 700 Hi-Strength in 0.48 BMT, which is why low skillion roofs are usually Trimdek or Klip-Lok. Full list: Custom Orb (corrugated, 762 mm cover): 5° (1.05/12); Trimdek (trapezoidal, 762 mm cover): 2° (0.42/12); Klip-Lok 700 Hi-Strength 0.48 BMT (700 mm cover): 1° (0.21/12); Klip-Lok 700 Hi-Strength 0.42 BMT (700 mm cover): 2° (0.42/12).
Can I use colorbond steel below the minimum pitch?
No. Below the minimum the covering is not code-compliant and manufacturers will not warrant it, because water drains too slowly and can be driven under laps. The lowest option on this page is klip-Lok 700 Hi-Strength 0.48 BMT (700 mm cover) at 1° (0.21/12); below that, choose a different roofing system from the minimum pitch chart.