Roof Flashing Repairs & Replacement
Flashing is the metalwork that seals every join and penetration in your roof, and it's the single most common place roofs actually leak. We repair and replace it properly.
What is roof flashing and why does it leak?
Flashing is the metal strip or sheet installed at every join, penetration and change of direction on your roof, around chimneys, valleys, walls, vents and pipes, to stop water getting underneath the roofing material. It leaks when it corrodes, lifts, cracks, or was poorly fitted in the first place. Because these are exactly the points where water naturally concentrates, damaged or badly installed flashing is the single most common cause of roof leaks.
Roof Flashing
The part of your roof most likely to leak
Ask any roof plumber where leaks actually start and the answer is usually flashing, the metalwork fitted at every join, penetration and change of direction on a roof. Chimneys, skylights, valleys, vents, pipes, and anywhere a wall meets a roofline all need flashing to stay watertight, and all of them are common leak points when that flashing fails.
Ready Plumbing repairs and replaces roof flashing on tiled and Colorbond roofs across the Northern Beaches and North Shore, as part of our full roof leak detection and repair service.
Why Flashing Fails
Why flashing fails
- Corrosion: Metal flashing degrades over time, especially in coastal salt air, until it no longer seals properly.
- Lifting and movement: Fixings work loose, or the flashing itself lifts slightly, leaving a gap for wind-driven rain to exploit.
- Poor original installation: Insufficient overlap, the wrong profile for the roof type, or gaps left at joins during construction.
- Age and general wear: Sealant dries out and cracks, and flashing that’s decades old simply reaches the end of its working life.
Wind-Driven Leaks
Why some leaks only show up sometimes
A leak that appears only in certain storms is a classic flashing symptom. Wind-driven rain gets forced sideways and upwards into gaps that vertical rain never reaches, which is why a roof can handle ten ordinary downpours and fail in the eleventh. We inspect for these specific vulnerable points, not just the obvious ones.
Repair Or Replace
Repair or replace
Most flashing problems are repairable: resealing, refixing, or replacing a single section where corrosion or damage is isolated. Full flashing replacement makes sense where corrosion is widespread or the original installation was inadequate across the board. We inspect first and give you a straight recommendation either way, priced before any work starts.
For the roofing material itself, see Colorbond roofing or the general roof leak repairs service.
Last reviewed: 23 July 2026 by the Ready Plumbing team.
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FAQ
Roof Flashing Repairs: your questions answered
Plumbing problems can be extremely frustrating. Our licensed Sydney plumbers are here to provide fast, reliable answers and solutions.
How do I know if my flashing is the problem?
If a leak appears near a chimney, skylight, roof valley, or where a wall meets the roof, flashing is the most likely cause. It's also common for leaks to only show up in certain storms, when wind drives rain up and under a lifted or gapped section of flashing that vertical rain never reaches.
Can flashing be repaired, or does it need replacing?
Isolated lifting or a failed seal can often be repaired: resealed, refixed or a section replaced. Flashing that's corroded through, or was undersized or badly installed originally, is better replaced properly than patched again. We'll show you what we find before recommending either.
Why was my flashing installed badly in the first place?
It's a detail-heavy part of roofing that's easy to rush: the wrong profile, insufficient overlap, or gaps left at joins. It often doesn't leak immediately, which is why poor flashing work can go unnoticed for years until a particular storm finds the weak point.
Does flashing repair require removing roof tiles or sheets?
Sometimes, depending on the location and type of roof. We assess the access needed as part of the inspection and include it in the quote, so there are no surprises once the job starts.
Is flashing repair urgent?
If it's actively leaking, yes, water finds its way into ceiling cavities and timber framing quickly. If you've just noticed a stain or damp patch, it's worth having it checked before the next heavy storm rather than waiting for it to get worse.
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Ready Plumbing is a Sydney-based and fully-licensed plumbing business with more than 20 years of experience, offering a range of residential and commercial plumbing solutions and emergency plumbing 24/7. Get in touch and we'll respond promptly.
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