Month: August 2025

Metal roofs are renowned for their sturdiness and are designed to outlast most other materials, resist fire, and stand up to Australia’s tough weather. They offer a variety of benefits, including being lightweight, highly energy-efficient, and often reflecting heat, keeping your house cool rather than absorbing it.

However, even the strongest metal roofing systems can have their weaknesses. And fasteners are one of them!

At Roof Renewal SA, our experts have been helping residents and businesses across Adelaide to catch all sorts of roofing problems, be it leaks, breakage, or replacement. Our motto is to be the first to respond and provide solutions that save you the maximum money!

Getting back on track, one of the most common culprits of leaks in metal roofs is loose or rusted screws that quietly let water seep in overtime. Fortunately, most of these problems can be averted with regular checks and a solid understanding of where trouble is usually found. Let’s dive in!

What Causes Metal Roof Leaks?

A hidden culprit of metal roof leaks is often installation errors, worn-out rubber washers, missed framing targets, corrosion, or sealant failure. Over the years, UV exposure and temperature changes can also degrade these components, causing water to seep through even the tiniest gaps.

Let’s break down what usually goes wrong in such cases:

1. Fastener Malfunctions

Screws must be installed exactly right. 

• If they are driven in too hard, the rubber washer beneath gets squashed and can’t do its job.
• If they are too loose, there’s a gap where water can creep through. 
• If the screw is at an angle, the washer won’t sit flat, which also weakens the seal. 

These small mistakes are more common than you’d think, especially in DIY or rushed installations.

2. Screws That Miss Their Mark

Every screw should anchor into solid timber or a purlin underneath the roofing sheet. However, we often find screws that are misplaced, as they’re simply sitting in the metal sheet with no support behind them. This means the washer doesn’t compress properly, and without that snug fit, water finds a way in. It’s something we check for during every inspection. 

3. Worn-Out Washers

If you’re someone who has overlooked their roofs for longer than you can think, then there’s a high chance that your rubber washers are beginning to wear out. Especially after years of exposure to the sun and seasonal weather fluctuations, it’s common to find this problem

Be mindful that around the 7 to 12-year mark, rubber washers can crack or brittle, and once that seal is compromised, even the best-placed screw can leak. 

Performing regular checks and replacing washers at the right time can help prevent small leaks.

4. Corrosion and Weather Stress

The metal expands and contracts with the seasons, and that’s exactly why constant movement slowly loosens screws and weakens the watertight seal. 

When dust or moisture accumulates around the screw head, corrosion begins to take hold very quickly. During the course of time, rusted screws can fail completely, leaving visible stains and even holes.

5. Poor Sealing Around Flashings

Sometimes the issue isn’t the screw itself, it is the flashing around it. 

If the sealant around penetrations (such as vents, chimneys, or skylights) is not applied correctly or has worn out, it becomes another weak spot. Combine that with shifting metal, and leaks become almost inevitable. That is why a comprehensive system inspection is always better than just checking for obvious defects.

What to Look For During Routine Roof Checks

You don’t need to get up on the roof to spot early signs of trouble. From ground level or during routine home checks, keep an eye out for:

• Cracked or missing rubber washers beneath screw heads
• Rust stains on roofing sheets, walls, or ceilings
• Pooling water or debris near screw lines
• Screws that appear uneven, loose, or slightly lifted

If you notice any of these issues, it’s best to have your roof inspected before the next storm rolls in and exacerbates the problem.

Simple Preventive Steps That Make a Big Difference

Most roof issues don’t start with something big; they begin with something small that’s left unnoticed for too long. But a few mindful checks can make all the difference in keeping your home safe, dry, and protected year-round.

• Replace washers every 7–12 years, especially in high-sun or weather-exposed areas
• Check that all screws are properly aligned and secured
• Use the right torque; too tight can split the washer, and too loose weakens it
• Clear the roof surface regularly of leaves, branches, and debris
• Reapply flexible sealant around joints, flashings, and penetrations every few years

Final Word

Roofs do a lot of heavy lifting, so they deserve the same care as the rest of the home. These small tasks might seem insignificant, but they prevent water damage, heat loss, and unnecessary stress down the line.

If you’re not sure what condition your roof is in, you’re not alone. That’s exactly why we’re here. At Roof Renewal SA, we take the time to check every screw, seal, and join so you don’t have to worry when the weather rolls in.

Book your roof inspection today. One simple check can save you a lot later.