Repair is usually right when…
- One leak traces back to a single flashing, penetration or a few fixings
- Sheets or tiles are sound and the coating is intact
- Damage is from one event (for example a storm) and the rest of the roof is fine
Replacement is usually right when…
- Rust has gone through sheets in several places, or tiles are cracking across the roof
- Multiple leaks keep recurring
- Battens or underlay are rotting
- Re-screwing and repainting would cost a large share of a new roof
Consent and the 15-year line
Routine maintenance and normal re-roofing of a roof more than 15 years old with like-for-like cladding doesn't need consent. But repair or replacement where a roof failed within 15 years does 1.
Insurance
Insurers generally cover sudden damage but exclude gradual deterioration and wear and tear 23. An old, rusting roof is usually a maintenance cost, not a claim. See re-roof insurance.
Still unsure? Read signs your roof needs replacing or tell us about your roof and we'll put you in touch with a local roofer who can inspect it and advise.
Frequently asked
Is re-screwing a roof worth it?
On a sound roof, re-screwing with new fixings can extend its life. On a roof with widespread rust, it rarely is.
Sources
- MBIE Building Performance — Recladding roofs (building consent requirements clarified)
- ICNZ — Gradual damage consumer guide (March 2024, PDF)
- Insurance & Financial Services Ombudsman — Gradual damage
Figures are published planning ranges, checked 26 October 2026. They are not quotes.