Tile and Metal Roofing: How Proper Roof Flashing Protects Your Home

Picture this: it’s a stormy Sunday in Sydney. Rain lashes against the windows, gutters groan under the downpour, and you’re inside enjoying a hot cuppa. Then—drip. Right onto the coffee table. That small leak? Chances are it’s not the tiles or the metal sheets to blame. It’s the flashing.

Many homeowners don’t even know what roof flashing is until water starts appearing where it shouldn’t. Yet, it’s one of the most important players in keeping a house dry.

What Is Roof Flashing?

Simply, roof flashing is thin stuff—usually aluminium, copper, or galvanised steel—put in at weak spots on a roof. Imagine valleys, skylights, chimneys, and where a roof abuts a wall.

Its purpose is to channel water away from these weak spots and into the gutters. Without it, water seeps into crevices, decays timbers, and turns plasterboard into wet Weet-Bix.

Both tile and metal roofing depend on flashing, but the installation method and areas of concern are different.

Flashing for Tile vs Metal Roofs

Tile Roofs

Whereas tile roofs—prevalent in suburbs such as Castle Hill, Parramatta, and the Inner West—are typically stepped or layered flashing to follow the overlapping design of the tiles. The problem? Tiles move with time, particularly on old buildings. A slipped tile might show flashing or create gaps for water to seep in.

Metal Roofs

For metal roofing, common in coastal towns such as Manly or North Wollongong, flashing is most often continuous and folded into sharp shapes. Metal roofs expand and contract with heat, so flashing must be put in with room for movement. If it’s too stiff, it will crack at the bends, allowing water in.

Why Flashing Fails

Flashing doesn’t “wear out” overnight. It’s most often a gradual accumulation of tiny problems:

• Rust — particularly in beach suburbs where salt spray speeds the corrosion.

• Poor installation — misplaced nails or flashing not properly tucked away.

• Blocked gutters — water flows back and creates a new route… into your ceiling.

• Movement in the roof structure — heat, cold, and settling foundations all cause minute movements.

One of the Marrickville roofers I interviewed likened poor flashing to a sketchy umbrella: “It still looks like it’ll do the job, but water just laughs and finds its way in.”

How Varying Suburbs Affect Roofing Requirements

A Balmain house is not identical to a Castle Hill house. That’s not simply the architecture—it’s also the climate your roof is exposed to.

Inner West residences usually contain heritage restrictions. That’s to say original tile profiles or traditional flashing details need to be maintained, which can restrict repair alternatives.

North Shore residences are located under heavy tree cover, so leaf litter accumulates quickly in valleys and behind flashing.

Coastal suburbs such as Manly have to contend with salt corrosion—flashing has to be stainless steel or high-grade aluminium to survive.

Western Sydney houses receive hotter roof surfaces, which can lead to additional expansion and contraction in metal roofing.

Understanding your suburb’s unique issues can be the difference between a flashing repair that will last five years and one that will last twenty.

Signs Your Flashing Could Be Failing

Homeowners usually think a leak indicates a cracked tile or a loose sheet. But flashing issues are more insidious.

Check for:

• Water stains on interior walls or ceilings next to chimneys or skylights.
• Lifting edges or rust spots along valleys or roof-to-wall transitions.
• Mould spots in the ceiling (a dead giveaway for slow, hidden leaks).
• Drips that only show up in one direction (water could be blowing underneath damaged flashing).

If you feel safe on a ladder, you can inspect flashing visually. But don’t tread on a roof you don’t know how to walk on—it’s dangerous, slippery, and can invalidate warranties.

Why Flashing Repairs Are Easily Neglected

Many homeowners will touch up eaves, clean gutters, or retile broken ones before they’ll even consider flashing. Why? Because it’s not as conspicuous as missing shingles or corroded downpipes.

It’s like the gasket in your car engine—out of sight, out of mind… until it fails. By the time flashing issues are visible inside your home, water may have already damaged rafters, insulation, and plasterboard.

DIY vs Professional Flashing Work

Could you flash it yourself? Sure, theoretically. You can purchase rolls of metal and sealants at Bunnings. But flashing is not merely preventing water today—it has to function through years of rain, wind, and temperature fluctuations.

A poor patch job can actually direct water into your roof cavity. And let’s face it—roof work is one of those things where gravity is the worst enemy.

For most people, it’s safer and more cost-effective to get a professional to inspect and replace flashing properly, especially on metal roofing where folding precision matters.

Maintenance Tips for Long-Lasting Flashing

If you’re keen to extend the life of your flashing:

• Clean gutters and valleys twice a year – debris build-up is flashing’s biggest enemy.
• Trim overhanging branches – less leaf litter, less moisture trapped around flashing.
• Inspect after heavy storms – search for wind-lifted edges or debris wedged behind flashing.
• Don’t neglect the ceiling. Consider upgraded materials – if you’re on the coast, use marine-grade metals.

Preventative work upfront saves thousands in ceiling and timber repairs in the future.

A Quick Story from the Inner West

I used to know a couple in Petersham who believed they had a plumbing leak. They’d hired a plumber twice—no solution. Ultimately, a roofer discovered the issue: a piece of rusty valley flashing behind the second course of tiles. Each big storm allowed water to run down the cavity and into their living room wall. The solution? A couple of hours of replacing flashing. Cost? A tiny fraction of what they’d already paid pursuing the incorrect cause.

Moral of the story—never underestimate the little bits of metal on your roof.

Why This Matters for Every Homeowner

Tile and metal roofing might look worlds apart, but both depend heavily on well-installed, well-maintained flashing. Without it, even the best roof will fail faster.

And because flashing problems often hide until damage is done, it’s one of those jobs worth understanding before trouble starts.

Next time you’re up the ladder clearing leaves, sparea glance at your flashing. A small check now might save you from that dreaded mid-storm drip.