P
Plan
Repair or replace — the decision framework
The real issue
A roofer inspecting your roof has a financial incentive to recommend the more expensive option. That does not make them dishonest — replacement may genuinely be the right answer. But you need independent confirmation before a $15,000–$30,000 decision, especially when the recommendation comes from the same person who will profit from it.
| Situation | Likely answer |
|---|---|
| Storm damage to a section of tiles, roof is 10 years old | Repair — isolated damage, roof has life remaining |
| Flashing failed around a skylight or pipe | Repair — flashing replacement is standard maintenance |
| Concrete tiles, 30+ years old, widespread cracking and spalling | Replace — end of life, widespread failure |
| Colorbond sheeting, 20 years old, coastal location, widespread surface corrosion | Replace — accelerated coastal degradation |
| Repair cost quoted at 60–70% of replacement cost | Replace — economics favour replacement |
| 20% of tiles cracked after hail, rest of roof sound | Repair — localised damage, replacement not warranted |
| Roofer says sarking and battens are "compromised" | Independent inspection — verify before deciding |
| Roof is 15 years old, roofer recommends full replacement | Second opinion — 15 years is mid-life for most AU roofs |
P
Prepare
AU roof lifespans — what to expect by material
| Roof type | Expected lifespan | Factors that shorten it |
|---|---|---|
| Concrete tiles | 25–50 years | Poor installation, moss/lichen buildup, re-bedding neglected |
| Terracotta tiles | 50–100+ years | Mortar failure at ridges and hips (tiles outlast the mortar) |
| Colorbond steel (standard) | 25–40 years | Coastal salt air, industrial pollutants, incorrect installation |
| Colorbond steel (coastal grade) | 30–40 years | Damage to coating from impact or foot traffic |
| Zincalume/galvanised | 15–25 years | Contact with copper or lead (galvanic corrosion) |
| Timber shingles/shakes | 20–30 years | Inadequate ventilation, moss, lack of treatment |
QLD/WA cyclone rating note: In cyclone-rated zones (most of QLD north of the Tropic of Capricorn, coastal WA, NT), roof systems must meet specific wind rating standards. If your property is in a cyclone zone and your roof predates current standards, a full replacement may bring required compliance upgrades. Check with your local council if this applies to you.
The 50% rule: When repair costs approach 50% of replacement cost, replacement typically offers better long-term value — you reset the lifespan clock, get a warranty, and may gain an insurance claim trigger point if the damage is storm-related. Run the numbers both ways before deciding.
I
Assess
Getting an independent inspection — what it should include
An independent roof inspection costs $200–$400 in most AU markets. It should be performed by a licensed builder or roofing inspector who has no financial interest in what they recommend. Do not accept a "free inspection" from a roofer quoting the work — it is a sales tool, not an independent assessment.
What a genuine inspection produces: A written report with photos identifying specific issues, their severity, and recommended action. "Needs full replacement — quote to follow" is not a report. Ask for the report before the quote.
| Inspection should cover | Why it matters |
|---|---|
| Tile/sheet condition across full surface | Identifies proportion of damage — drives repair vs replace decision |
| Ridge caps and hip capping | Mortar failure here is common and repairable — separate from roof surface condition |
| All flashing points (skylights, pipes, walls, chimneys) | Most leaks originate at flashings, not the roof surface itself |
| Valley condition | Debris accumulation and valley deterioration is a common leak source |
| Sarking and battens (visible sections) | Compromised sarking is a genuine replacement indicator — needs to be verified, not assumed |
| Gutters, downpipes, fascia | Often quoted separately — knowing their condition prevents surprise add-ons mid-job |
Insurance claims: If the damage follows a storm, hail, or extreme weather event, contact your insurer before any repair work begins. Authorising repairs before lodging a claim can void your entitlement. Your insurer will arrange their own inspection — you are entitled to be present for it and to request a copy of the report.
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Cost
What roof repair and replacement costs in Australia
| Work | Typical AU range | Notes |
|---|---|---|
| Independent inspection (written report) | $200–$400 | Worth doing before committing to any significant work |
| Re-bedding and re-pointing ridge caps | $800–$2,500 | Common maintenance item on tile roofs 15+ years old |
| Flashing replacement (per penetration) | $300–$800 | Skylights and chimneys at higher end of range |
| Tile replacement (per tile, supply and fit) | $50–$150 | Matching tiles add cost on older roofs |
| Colorbond sheet repair/replacement (per sheet) | $150–$350 | Profile matching may be required on older installations |
| Full tile roof replacement (avg home) | $15,000–$35,000 | Higher end for complex rooflines, steep pitch, sarking included |
| Full Colorbond replacement (avg home) | $12,000–$28,000 | Varies significantly by roof area and complexity |
| Gutter replacement (per linear metre) | $35–$80 | Often quoted as a separate line item in full replacements |
The question to ask any roofer recommending replacement
"Can you show me, specifically, the areas where repair is not viable — and explain why repair isn't an option for each one?" A roofer who can walk you through this with photos and specific reasons is giving you a defensible recommendation. One who gives a general answer about "overall condition" without specifics is not.