What is actually different?
| Question | Corrugate | Five-rib / trapezoidal |
|---|---|---|
| Appearance | Repeated rounded waves | Raised angular ribs with flatter pans Sources: Metalcraft Corrugate; Metalcraft MC760. |
| Published pitch examples | Metalcraft Corrugate: 8° | Metalcraft MC760: 3° Sources: Metalcraft Corrugate; Metalcraft MC760. |
| Effective cover in these examples | 760 mm | 760 mm Sources: Metalcraft Corrugate; Metalcraft MC760. |
| What to compare on a quote | Named profile, metal, coating, thickness and accessories | The same specification and scope |
Think of the specification as four separate decisions: shape, base metal, protective coating and installed system. Asking only for “COLORSTEEL” does not identify the shape; asking only for “five-rib” does not identify its coating or gauge. A useful quote names all four.
Which NZ product names mean five-rib?
Metalcraft MC760 and T-Rib are trapezoidal choices. Dimond calls its five-rib profile Hi Five. Similar-looking profiles are not interchangeable order codes. Confirm the local branch, exact cover and matching ridge, hip and valley details. Sources: Metalcraft MC760; Metalcraft T-Rib; Dimond Hi Five.
Does five-rib cost more?
One public retail listing offers both steel profiles at $17.49 per lineal metre including GST. It describes 0.5 mm gauge steel but does not establish that it is the same specification as a locally quoted branded roof. This is a material listing, not installation evidence. Sources: Bitz & Piecez.
On the same effective cover, an identical lineal price produces an identical sheet-area cost. Where covers differ, compare price divided by effective cover in metres. Do not use the overall sheet width, because side laps would then be counted as usable roof.
| Input | Sheet A | Sheet B |
|---|---|---|
| Price used for the example, not a supplier offer | $25/lm | $25/lm |
| Assumed effective cover | 0.760 m | 0.840 m |
| Calculated sheet-only cost | $32.89/m² | $29.76/m² |
The arithmetic shows why a material ranking should not be forced to match an expected installed ranking. It says nothing about whether these two hypothetical sheets have equivalent coatings, warranties or structural performance.
Use the numbers you know
Convert a sheet price
Enter your own prices and dimensions to calculate. This tool does not supply a market rate or add GST.
Where can the installed difference come from?
Installation differences should be explained in the quote rather than assumed from a profile name. Ask whether angled cuts and profile-matched ridge and hip work change the labour on your particular roof. The useful comparison is the finished scope, not a universal five-rib surcharge.
Ask the roofer where the additional work is priced. If cut sheets, notched flashings and complex junctions are already priced as separate components, adding another blanket “complex roof” allowance for the same tasks can double-count them.
- Compare the same roof area and the same plan-versus-slope basis.
- List ridge, hip, valley and barge lengths separately.
- Confirm underlay, fixings, delivery and wastage.
- Separate old-roof removal and access from the new covering.
What do real projects tell us?
Publisher-reported project
Keeping a villa roofline
Herne Bay, Auckland · True Oak corrugate
Roofing Industries describes a Lowndes reroof using its corrugated profile on a low-pitch section.
What it illustrates: A profile-specific solution can matter more than a generic material category. This case does not establish a minimum pitch for every corrugated roof.
- Roof price
- Not published
- Measured area
- Not published
Publisher-reported project
A two-day long-run replacement
Hibiscus Coast, Auckland · Trim Rib
HDK reports a two-day reroof with Trim Rib, new flashings and timber strengthening.
What it illustrates: This is one reported job duration, not a promise for a different house.
- Roof price
- Not published
- Measured area
- Not published
These two jobs illustrate design constraints and scope. Neither publisher supplies enough cost and area information to calculate a defensible price difference between profiles.
What should you ask for next?
For an existing roof, start with its pitch, condition and junctions. For a new design, compare the desired appearance alongside drainage and support requirements. Then request two like-for-like specifications rather than two vague “metal roof” totals.
- Write down the exact manufacturer and profile.
- Ask for base metal thickness and coating name, not just colour.
- Confirm suitability for the site and the roof’s lowest-pitch section.
- Ask the contractor to explain any difference in labour or accessory cost.
Related questions
Is five-rib the same as COLORSTEEL?
No. Five-rib describes a profile family. COLORSTEEL names a material range; the exact profile and coating product still need to be specified. Sources: Metalcraft MC760; COLORSTEEL.
Sources and review notes
Prepared by RoofHub editorial team. Reviewed . A source check confirms what a page states, not an independent inspection or invoice audit. Published project accounts are attributed to their publishers.
- primaryMetalcraft: Corrugate product specifications - Page checked 2026-09-28. Publication date not stated. · manufacturer
- primaryMetalcraft: MC760 product specifications - Page checked 2026-09-28. Publication date not stated. · manufacturer
- primaryMetalcraft: T-Rib product specifications - Page checked 2026-09-28. Publication date not stated. · manufacturer
- primaryDimond: Hi Five product specifications - The overview states 765 mm cover, while the performance section states 755 mm. RoofHub flags this conflict rather than choosing an ordering width. Page checked 2026-09-28. Publication date not stated. · manufacturer
- marketBitz & Piecez: Roofing products and public prices - Retail listing, not a like-for-like COLORSTEEL specification. Thickness is described as gauge, not confirmed BMT. Effective cover must be confirmed before converting to square metres. Page checked 2026-09-28. Publication date not stated. · supplier
- primaryRoofing Industries: Herne Bay villa with True Oak corrugate - Manufacturer-reported project, not an independently audited result or published quote. Page checked 2026-09-28. Publication date not stated. · manufacturer
- marketHDK Longrun Roofing: Long-run reroof, Hibiscus Coast - Page checked 2026-09-28. Publication date not stated. · contractor
- primaryCOLORSTEEL: The evolution of COLORSTEEL - Page checked 2026-09-28. Publication date not stated. · manufacturer
Original calculations are labelled as examples. Historical prices stay dated, missing fields stay unknown, and conflicting specifications are flagged. Sources are not endorsements or paid rankings. Read our methodology or report a correction.
Keep exploring
Apply this to your roof
Have measurements or a project question?
Use your dimensions in the detailed estimator, or send your question to the RoofHub team. A roofing contractor still needs to confirm the site, specification and final price.