Rust Treatment & Metal Sheet Replacement Northern Rivers
Rust on a metal roof is usually fixable before it becomes a re-roof. On Northern Rivers homes, coastal salt attacks the exposed steel at cut edges, overlaps and screw holes first. We treat surface and cut-edge rust with rust converters and coastal-grade coatings, and replace sheets that have rusted through. The key is catching it early — a treated lap costs a fraction of a replaced sheet.
Why this matters on the Northern Rivers coast
Rust is the single biggest killer of metal roofs on the coast, and the Northern Rivers gets it from both directions — salt spray off the ocean and high UV that breaks down protective coatings over time. The first place rust shows up is almost never the flat field of the sheet; it's the cut edges, the overlaps and the screw holes, where the steel is exposed and moisture sits. Catch it there and you treat it; leave it and it pits through the sheet and you're looking at replacement.
A lot of what looks like rust on a metal roof isn't actually the sheet rusting at all — it's swarf, the fine steel filings left from cutting sheets or driving screws, rusting onto the coating. The two need different fixes, so we always distinguish them before quoting. Treating a few rusty laps early is one of the cheapest things you can do to extend the life of a metal roof; replacing the whole thing is the most expensive. We'll show you exactly where you sit on that scale.
Signs you need this
- Orange or brown stains at sheet overlaps and cut edges
- Rust streaks running down from screw heads
- Rust appearing on the ocean-facing side of the roof
- Pitting or small holes in the sheet metal
- Flaking or bubbling of the roof coating
- Swarf (metal filings) rusting onto the surface — looks like rust but wipes off
What we do, step by step
- 1
We inspect the whole roof, photograph all rust, and distinguish genuine rust from swarf staining.
- 2
Surface rust is treated: loose rust removed, rust converter applied, primed and coated in a colour-matched coastal-grade finish.
- 3
Cut-edge and lap rust is treated and sealed with a flexible roofing sealant to stop moisture re-entering.
- 4
Sheets rusted through are replaced with matching profile and colour, laps sealed and re-screwed with Class 4 fixings.
- 5
All swarf is cleaned off so it doesn't keep staining the coating.
- 6
You receive a before/after photo report and a written workmanship warranty.
What's included
- Full roof inspection with all rust photographed, genuine rust distinguished from swarf
- Surface rust treated: loose rust removed, rust converter, primer, colour-matched coastal topcoat
- Cut-edge and lap rust treated and sealed with flexible roofing sealant
- Sheets rusted through replaced with matching profile and colour, laps sealed
- All swarf cleaned off so it stops staining the coating
- Before/after photo report and written workmanship warranty
Materials we use — and why they suit coastal homes
We use rust converters, marine-grade metal primers, and colour-matched coastal topcoats compatible with Colorbond. Replacement sheets are matched to your existing profile and colour. All re-fixing uses Class 4 (AS 3566) coastal-rated screws.
How much does it cost?
from $400 for localised rust treatment — sheet replacement quoted after inspection
Treating a few rusty laps is affordable. Replacing individual rusted sheets costs more but is still far cheaper than a full re-roof. We photograph the extent and give you a fixed quote — and an honest call on whether treatment or replacement is the better spend.
Repair, restore or replace?
Localised rust on otherwise-sound sheets: treat and seal. Rusted-through sheets or widespread rust: replace the affected sheets (staged) or, if the whole roof is failing, re-roof. We show you photos of every rust spot and a cost comparison so you can decide with confidence.
Before & after
