Roof Flashing Repair & Replacement in Perth

What Is Roof Flashing and What Does It Do?

Roof flashing is the thin metal material — typically lead, Colorbond, or aluminium — installed wherever your roof meets another surface or has a penetration. These include chimneys, vent pipes, skylights, wall-to-roof junctions, parapet walls, and any other point where the continuous tile or sheet surface is interrupted.

Flashing works by creating an overlapping barrier that directs water away from vulnerable joints and back onto the roof surface or into the gutter system. When flashings are correctly installed and maintained, they provide a reliable seal against Perth’s driving rain. When they fail, however, they become one of the most common sources of persistent roof leaks.

Common Types of Flashing on Perth Roofs

Perth homes feature several types of flashings, each designed for a specific function:

• Chimney flashing — Typically a combination of step flashing (along the sides), back flashing (uphill side), and an apron (downhill side). Chimneys are especially leak-prone because they involve multiple flashing pieces meeting at different angles.
• Vent pipe flashing — Rubber or lead boots that seal around plumbing vents, range hood exhausts, and bathroom extraction fans penetrating the roof.
• Skylight flashing — A continuous metal frame that integrates the skylight into the surrounding tile or sheet roof. Factory-made skylight flashing kits are available, but many Perth installations require custom adaptation.
• Wall junction flashing — Where a lower roof meets a higher wall, such as in two-storey homes, granny flats, and extensions. This type includes both top flashing (chased into the wall) and a soaker beneath the tiles.
• Parapet and box gutter flashing — Found on flat or low-pitch commercial and residential roofs where walls extend above the roof line.

Why Flashing Fails in Perth

Flashing failures across Perth homes are driven by several factors:

• UV degradation — Perth’s relentless sun degrades rubber boots, silicone sealants, and bituminous compounds within 5 to 10 years, causing them to crack and pull away.
• Thermal movement — Repeated heating and cooling causes metal flashings to expand and contract, eventually loosening fixings and breaking sealant bonds.
• Poor original workmanship — Many Perth homes have flashings that were installed with insufficient overlap, incorrect step heights, or excessive reliance on silicone caulk instead of proper mechanical installation.
• Corrosion — Galvanised flashings near the coast corrode from salt exposure. Dissimilar metal contact (such as lead against Zincalume) can also cause galvanic corrosion.
• Building movement — Settlement and minor structural movement in Perth’s sandy soil conditions can shift flashings out of alignment.

Our Flashing Repair and Replacement Approach

Our qualified roof plumbers assess each flashing failure individually and recommend the most appropriate repair or replacement method:

1. Inspection — We examine all flashings on your roof, not just the one that appears to be leaking. Flashings of similar age and material are likely at a similar stage of deterioration.
2. Material selection — We use lead for chimney and complex penetration flashings due to its malleability and longevity. For wall junctions and simpler applications, Colorbond offers a cost-effective and corrosion-resistant solution.
3. Proper installation — Every flashing is installed with the correct overlap, step height, and turn-up dimensions specified by Australian Standards. We do not rely on sealant alone — mechanical fixing and correct overlap are the primary waterproofing method.
4. Sealant application — High-quality polyurethane or neutral-cure silicone sealant is applied as a secondary defence at critical joints, selected for UV and heat resistance suitable for Perth conditions.
5. Testing — After installation, we water-test the repaired area to confirm the seal is effective before we leave the site.

When to Repair vs When to Replace

Minor flashing issues — such as a small sealant failure or a single lifted edge — can often be repaired without full replacement. However, if the flashing material itself is corroded, perforated, or has been previously patched multiple times, replacement is the more cost-effective long-term solution.

We always advise honestly on whether a repair will hold or whether replacement is the smarter investment. Our goal is to give you a permanent fix, not a temporary patch.

Get a Free Flashing Inspection

If you have noticed water stains near a chimney, skylight, or where an upper wall meets your roof, there is a strong chance the flashing needs attention. Contact us for a free inspection across the Perth metro area. No call-out fee, no obligation.