I’m the founder and lead building inspector at WA Building Inspections Perth. Over the years, I’ve climbed more roofs than I can count, and one thing remains true: most people focus on the wrong things when inspecting a roof. Sure, cracked tiles are an issue—but it’s often the smaller, overlooked details like lead flashings that end up causing the most damage.

Let’s break down what I discovered in a recent terracotta roof inspection in Perth, and what it means for you as a buyer, seller, or property investor.

What Most People Miss During a Roof Inspection

It’s Not Just About the Roof Tiles

“When doing a roof inspection, it’s not just about the roof,” I said in my video. And I mean it.

Sure, we can talk about damaged tiles, lichen growth, or historic repairs—but what often goes unnoticed are the lead flashings. These are the thin sheets of metal used to direct water away from critical areas like chimneys, valleys, and where roofs join walls.

“Take the time to just have a look at these flashings… A lot of water can get in and around them if they’re not sealed properly.”

Unsealed or corroded flashings are prime entry points for water, especially in heavy rain. Water ingress here doesn’t just lead to a few drips—it can rot roof frames, damage ceilings, and cause mould throughout your home.

Lead flashings might appear intact at first glance, but small gaps, loose edges, or corrosion can be difficult to spot without experience. We see plenty of situations where home handymen or previous contractors used subpar materials to patch over flashing issues, only for them to fail a few years later.

If you’re buying a property in Rockingham to Mandurah, make sure your building inspection digs deeper than the surface. These coastal areas are especially vulnerable to corrosion due to the salt air.

How to Spot a Hidden Roof Defect

1. Look Beyond the Primary Elements

Most people scan for broken tiles and stop there. Don’t. Check for:

• Lead flashings that are loose, rusted or unsealed
• Signs of water pooling or previous patch jobs
• Undulation along ridge lines, which could indicate issues with the roof frame
• Discolouration of tiles or mortar, indicating water absorption over time
• Organic growth such as lichen and moss, which trap moisture and accelerate decay

“These ones are not looking to be in great condition generally… they can very easily be areas where water can pond.”

Even if there’s no active leak, the presence of historic repairs tells a story. Someone fixed something there for a reason. These areas are often repaired reactively, meaning the root cause might still exist—or could re-emerge during the next big weather event.

2. Functionality Over Aesthetics

When I see a dodgy-looking flashing that doesn’t match the roof, some clients ask, “Isn’t that a bit ugly?”

“We’re not here for the optics of the property. We’re here for functionality.”

That’s the right mindset. The question is simple: Will it cause water ingress? If yes, it’s a significant defect—even if it looks fine.

One key factor to remember: water takes the path of least resistance. If flashing is misaligned even slightly, water will find its way in. Then, the problem won’t stay on the roof—it travels down into insulation, roof framing, wall cavities, and even flooring.

Terracotta Roof Tiles: Beautiful but Brittle

Terracotta roof tiles are common across Perth, especially in established suburbs. While they offer excellent thermal and acoustic insulation, they’re also:

• Brittle and prone to cracking under weight
• Susceptible to moss, mould, and lichen buildup
• Prone to microcracking over time from expansion and contraction

I’ve said it before and I’ll say it again: “Be careful walking on terracotta roof tiles, just FYI.”

They might look solid, but aged terracotta tiles can crumble under pressure or become dislodged by wind. Cracked or shifted tiles are easy access points for moisture—especially if they’re hiding deteriorated underlay or broken battens beneath.

If you’re doing a roof inspection in Perth, make sure your inspector understands the fragility and waterproofing challenges that come with terracotta tiles.

Perth Roofs: Unique Risks and Why It Matters

WA’s harsh weather—hot summers and torrential rains—expose roofs to rapid wear. That’s why I always say, “look down those ridge beams and check for undulation.” It could be a sign the underlying substrate or timber frame is compromised.

Roof movement is common in older suburbs like Midland and Bassendean, especially where homes were built decades ago with timber that has now dried and twisted. In newer suburbs around Mandurah, salt-laden air introduces a different risk profile: accelerated corrosion, especially to lead and galvanised components.

Whether you’re in Perth, Mandurah, or Midland, these risks are real and recurring. Your home might have the same problems—and a regular glance from the ground won’t reveal them.

Case Example: What I Found on Site

In this inspection, I noticed several key defects:

• Flashings not properly sealed
• Terracotta tiles with microcracks—common with age
• Lichen growth on ridgelines
• Ponding areas that had no escape drainage
• Historic patching with a questionable finish

“They’ve been repaired for a reason. There was obviously an issue here at some stage.”

By investigating these subtle cues—like flashing work that doesn’t quite line up—we can often determine whether repairs were cosmetic or functional. If it’s the former, they’re likely just hiding an issue rather than fixing it.

Frequently Asked Questions (FAQs)

What is the most overlooked part of a roof inspection?

Lead flashings. These metal pieces direct water away from critical areas. If damaged, they can allow water ingress and structural damage. Flashings are often hidden under tile overlaps, making them easy to forget.

Are historic roof repairs a problem?

Not always, but they’re a sign that something went wrong in the past. Always investigate further. Past patch jobs should be properly inspected to make sure the root issue was resolved—not just covered over.

What does undulation in ridge beams mean?

It may indicate issues with the underlying roof frame or substrate—a sign of possible structural movement or poor workmanship. This can impact the entire roof alignment.

Can you walk on terracotta roof tiles during an inspection?

You can, but very carefully. I always say, “be careful walking on terracotta roof tiles, just FYI.” They’re brittle and prone to cracking under pressure, especially in hot weather.

How quickly can water damage occur?

With enough rain and a poorly sealed flashing, damage can happen within a single storm season. Mould and timber rot can set in surprisingly fast, especially in Perth’s humid summer conditions.

Are terracotta tiles better than concrete tiles?

Terracotta tiles offer better insulation and longer lifespan if maintained, but they’re more brittle. Concrete tiles are more durable under foot traffic but may not age as well visually.