What are Class 4 roof screws and why do they matter on the coast?

Class 4 (to AS 3566) is the highest corrosion-resistance rating for roofing screws. Coastal salt exposure means anything less will rust and fail prematurely. We use Class 4 screws on all coastal re-screws.

Can you re-screw just part of the roof?

No. A re-screw is done across the whole roof. Screws on the same roof are the same age and have had the same exposure, so if the washers are failing on one slope the rest aren't far behind. If only a few fixings have failed, that's a leak repair, not a re-screw, and we'll quote it that way.

Why is swarf removal important?

Swarf is the fine metal filings left when screws are driven in. If left on a Colorbond roof, those filings rust and stain the coating — looking like the roof itself is rusting. We clean all swarf off on every re-screw job.

My roof leaks when the wind drives rain — is it the screws?

Very often, yes. Wind-driven rain pushes water past failed screw washers that would hold up in normal rain. A re-screw with new sealed screws usually fixes it.

Do you warranty the re-screw work?

Yes — all re-screws come with a written workmanship warranty, plus a photo report showing the screws replaced and any rust treated.

Home/Roof Repairs/Metal Roof Re-Screws Lennox Head & Northern Rivers

New Class 4 roof screws along the flashing of a metal roof after a re-screw in Lennox Head

Metal Roof Re-Screws Lennox Head & Northern Rivers

Metal roof re-screwing replaces failed, rusty or loose screws with new Class 4 corrosion-resistant fixings (to AS 3566) suited to coastal exposure. On Northern Rivers homes, salt air and UV perish the rubber washers under screws within 10–15 years, letting water in and causing sheets to rattle or lift in storms. A proper re-screw stops leaks and extends the life of your Colorbond roof.

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Signs you need this

Rust stains forming around screw heads
Screws missing, backed out or spinning loose
Leaks appearing after wind-driven rain
Cracked or perished rubber washers visible at the edges
Roof sheets rattling or lifting in strong wind
Brown streaks running down from fixings

Close-up of a rusted roof screw on a corrugated metal roof in Lennox Head — Rust has eaten into the screw head, a sign the coating is gone.

Rusted hex-head roof screw with an ageing washer on corrugated sheeting — Rusted hex head with an ageing washer. This is where leaks start.

Row of rusted screws along a metal roof ridge cap — A whole row of rusted fixings along the ridge cap.

Rusted roof screws along the flashing of a corrugated metal roof in Lennox Head before a re-screw — Lennox Head job: every screw along this flashing had rusted through, before we replaced them.

What we do, step by step

1
We inspect the whole roof and photograph every issue, including a close-up of suspect screw heads and washers.
2
Failed, rusty or loose screws are removed. Oversized screws are used where the existing holes have stripped or enlarged.
3
We install new Class 4 (AS 3566) corrosion-resistant screws sized correctly for your sheet profile and coastal exposure.
4
We check and re-seal laps, ridges and flashings, and treat any rust spots found at sheet laps.
5
All swarf (metal filings) is cleaned off the roof so it doesn't rust-stain the Colorbond coating.
6
You receive a before/after photo report documenting the work and the new fixings.

Watch a re-screw, start to finish

Filmed on a real Lennox Head job: we pull every rusted screw across the whole roof, drive in new Class 4 screws, then blow off the swarf so the filings can't rust-stain the Colorbond.

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Materials we use — and why they suit coastal homes

We use Class 4 roof screws rated to AS 3566 — the highest corrosion-resistance class, essential for homes within kilometres of the surf. Where existing holes are stripped, we step up to oversized screws for a solid bite. We match the screw profile to your sheet (corrugated, trimdek or klip-lok) and seal laps with quality coastal-grade sealants. Swarf is always cleaned away to prevent the false 'rust' stains that filings leave on Colorbond.

How much does it cost?

from $2,000 – every roof is quoted after inspection

The final price depends on roof size, pitch, number of storeys, access, and how many screws need replacing. We'll give you an itemised quote after inspection — no vague estimates.

Repair, restore or replace?

If only a few screws have failed, we replace those as a leak repair. Once washers are failing generally, the whole roof is re-screwed, because every fixing on it is the same age. If sheets are rusting through at the laps or the roof is past its service life, sheet replacement may be better value. A re-screw is also often required before an insurer will sign off on repairs. We'll show you photos and an honest recommendation either way.

Before & after

Rusted screws along the flashing replaced with new Class 4 coastal fixings — Lennox Head — after

BEFORE

AFTER

Rusted screws along the flashing replaced with new Class 4 coastal fixings — Lennox Head

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Frequently asked questions

On a beachfront or near-coast home in the Northern Rivers, expect screw washers to start perishing within 10–15 years. We recommend an inspection around the 10-year mark, and a re-screw of the whole roof once washers are failing — earlier than you would inland.