Apply the answer
Work through the condition before choosing the scope.
Use the symptoms, spread and repeat history first. RoofHub can help separate a plausible local repair from restoration, replacement or a case that needs inspection.
Safety comes before the repair-vs-replace question
Modern pressed-metal tiles are not the same thing as historic Decramastic products. Product identification, age/context and appropriate asbestos assessment/testing should be separated from the decision about whether the roof is worth repairing. Sources: NZ Metal Roofing Manufacturers; WorkSafe roof warning.
Once safe handling is established, condition still drives the scope
| Observed condition | More plausible next step | Why |
|---|---|---|
| One local defect, with otherwise serviceable roof and a safe compatible repair method | Targeted professional repair may be possible. | A contained failure does not prove the whole roof has failed. Sources: Roofing Association of New Zealand. |
| Surface/coating wear but no evidence of perforation or widespread system failure | Specialist assessment before any restoration proposal. | Safety, product compatibility and substrate condition must be established first. Sources: Roofing Association of New Zealand; WorkSafe roof warning. |
| Widespread coating loss, rust-through, multiple leaks or material failure | Reroof/replacement becomes more plausible. | Repairing many failing areas can leave the underlying roof system unreliable. Sources: Roofing Association of New Zealand. |
Questions to answer before requesting prices
- Is the roof product actually identified, or just assumed to be “Decramastic”?
- Has asbestos risk been assessed before any cleaning, cutting or removal?
- Are failures localised or across many roof faces?
- Is there rust-through/perforation or mainly coating/stone-chip wear?
- Are leaks isolated or recurring in multiple areas?
- If reroofing, what removal/containment/disposal method is included?
- What replacement system, underlay/battens/flashings and safety access are included?
Use the asbestos guide for identification and the condition guide for scope
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.
- primaryWorkSafe New Zealand: Check for asbestos before high-pressure spraying on roofs (2026-08-20) - WorkSafe safety alert published 20 August 2026 after incidents involving high-pressure roof spraying, including a 1970s Decramastic roof that tested positive for chrysotile asbestos. High-pressure water and compressed air must not be used on asbestos-containing material. Page checked 2026-10-21. Publication date shown above. · government
- primaryNZ Metal Roofing Manufacturers: Pressed metal tiles, Code of Practice - Page checked 2026-09-28. Publication date not stated. · industry-technical
- primaryRoofing Association of New Zealand: RANZ Re-Roofing Guide - RANZ describes this as an annually updated NZ consumer guide to reroofing materials, systems, terminology, scope and workmanship. Used for project-planning context rather than contractor ranking. Page checked 2026-10-21. Publication date not stated. · industry-technical
- primaryNZ Metal Roofing Manufacturers: Today’s metal tiles are not Decramastic (2016-05-09) - Historical explanation of coating changes. Its old supplier list and warranty references are not used as current market facts. Page checked 2026-09-29. Publication date shown above. · industry-technical
- primaryRoofing Association of New Zealand: Maintenance Tips - RANZ homeowner maintenance guidance covering drainage, signs of deterioration and working-at-height safety. Used as practical industry context alongside product-specific manufacturer requirements. Page checked 2026-10-21. Publication date not stated. · industry-technical
- primaryRoofing Association of New Zealand: New Zealand Roof Coating Code of Practice - RANZ roof-coating trade guidance. It states that roof coating is not weatherproofing, requires an initial roof-condition assessment, and only extends the life of a suitable existing roof for a limited time. Page checked 2026-10-21. Publication date not stated. · industry-technical
- marketAbove Focus Roofing: Decramastic tile roof leak identification and repair - Wellington contractor project page reporting a persistent Decramastic roof leak that previous repair attempts had not resolved. The page shows water at the building paper and replacement tiles and reports the leak was resolved. RoofHub uses it as a project-specific example that an older textured-metal-tile roof can sometimes receive a local repair; it does not establish asbestos status or prove that local repair is suitable for another roof. Commercial interest: sells roofing services. Page checked 2026-10-21. Publication date not stated. · practitioner observation
- primaryWorkSafe New Zealand: Working with or near asbestos - Page checked 2026-09-28. Publication date not stated. · government
- marketRoof Repair Specialists: Decramastic tile to COLORSTEEL - Torbay case study - Project-specific Auckland account describing a 1970s Decramastic roof with widespread stone-chip loss, rust-through and multiple leaks before full replacement. Publisher-reported project; not an independent inspection. Commercial interest: sells roofing services. Page checked 2026-10-21. Publication date not stated. · practitioner observation
- marketPaul Makuch Roofing: Re-roof vs roof restoration - Waikato roofing contractor comparison of restoration and reroofing. Useful for practitioner decision signals such as localised repairability versus widespread rust/failing sheets. Commercial service source; RoofHub does not treat its recommendation as independent technical proof. Commercial interest: sells roofing services. Page checked 2026-10-21. Publication date not stated. · practitioner observation
- marketRoof Repair Specialists: Reroofing services and recent reroof projects - Auckland contractor page with recent reroof examples and its stated repair/restoration/replacement distinctions. Commercial source; useful for field patterns and opening-up scope, not for universal lifespan claims. Commercial interest: sells roofing services. Page checked 2026-10-21. Publication date not stated. · practitioner observation
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
Next step
Estimate it, refine it, or ask RoofHub.
Start with approximate information, use actual measurements when you have them, or ask RoofHub to explain the decision. A roofing contractor still needs to confirm the site, specification and final quotation.