Flashing Installation
Flashings are among the most important waterproofing components on your roof, but they rarely get the attention they deserve. While tiles and metal sheeting get all the credit for keeping rain out, it’s the flashings — those strips and sheets of metal installed at joints, penetrations, and transitions — that seal the most vulnerable points in your roof system. Get them right and your roof stays dry through decades of Coffs Harbour weather. Get them wrong, and water finds its way in through gaps that are almost impossible to identify without knowing exactly what to look for.
At Roof Restoration Coffs Harbour, Nathan Locke and his team install new flashings across the Mid North Coast. With over 25 years of experience, full licensing, public liability insurance, and a 10-year warranty on all workmanship, we provide flashing installations that perform properly for the long term. Here’s what you need to know about flashings and where they’re needed.
What Are Flashings and Where Are They Used?
Flashings are thin sheets or strips of metal (or in some applications, flexible membrane material) installed at transitions, junctions, and penetrations in the roof to create a waterproof seal. Water follows the path of least resistance, and at any point where two surfaces meet or where the roof covering is interrupted, water can find its way through without flashing.
Flashings are needed at virtually every “break” in your roof — everywhere the continuous surface of tiles or metal sheeting is interrupted by a structural element, a fitting, or a change of plane.
Wall Flashings
Where the roof meets a wall — at a dormer, a parapet, a change of roof level, or where a lean-to addition meets the main roof — a wall flashing is required. This typically involves a step flashing that integrates with the roof covering course by course, and an apron or counter-flashing that covers the top of the step flashing and is embedded or sealed into the wall. Without correct wall flashings, water runs down the wall, enters the gap at the base of the wall and the roof surface, and penetrates the ceiling.
Penetration Flashings
Any element that penetrates the roof surface — pipes, conduits, roof vents, exhaust fans, whirlybirds, solar panel mounting brackets — creates a potential leak point. Penetration flashings are formed around the penetrating element and integrated with the roof covering so that water can’t enter around the penetration. This is one of the most common sources of roof leaks, and one of the most common occasions for new flashing installation when new roof penetrations are created.
Valley Flashings
Valleys — where two roof planes meet in a V-shape — are one of the highest-flow points on any roof. Water from both roof planes concentrates in the valley and flows at high volume during heavy rain. Valley flashings line the valley to ensure this water stays on the roof surface and flows to the gutter rather than finding its way through the junction. New valley flashings are installed when extending or adding new roof sections.
Skylight Flashings
Skylights create large penetrations in the roof surface that require comprehensive flashing on all four sides. Factory-supplied skylight flashings are typically included with the skylight unit and are installed as part of the skylight installation process. It’s critical that these flashings are correctly integrated with the roof covering — incorrect integration is the leading cause of skylight leaks.
Ridge and Hip Flashings
On metal roofing, ridge and hip caps act as flashings at the apex and hips of the roof. On tiled roofs, ridge caps are typically mortar-bedded or mechanically fixed tiles. New flashings at ridges and hips may be required when changing from tiled to metal roofing or when structural changes alter the roof geometry.
Eave Flashings
Eave flashings are installed at the base of the roof to prevent wind-driven rain from being driven back up under the roof covering. They’re particularly important on low-pitch roofs and in Coffs Harbour’s storm-prone environment where wind and rain combine to create significant horizontal water movement.
Importance of Flashings for Waterproofing
The roof covering — tiles, corrugated iron, Zincalume sheeting — is designed to shed water in the direction of flow, downslope. It’s not designed to be completely waterproof under all conditions, particularly at transitions and penetrations. Flashings are what make the whole system waterproof.
In Coffs Harbour, with its combination of high rainfall intensity and regular storm winds, the demands on flashings are significant. Wind-driven rain travels horizontally and can be forced up under the roof covering or through gaps that would never be reached by vertical rainfall. Flashings need to be correctly designed and installed to resist these conditions.
A roof without correctly installed flashings at all necessary locations isn’t a properly waterproofed roof — regardless of how good the tiles or sheeting are.
Types of Flashing Materials
Colorbond and Zincalume Steel
Colorbond and Zincalume are the most common flashing materials for residential roofs in Australia. Colorbond flashings can be colour-matched to the roof and gutters for a neat appearance, while Zincalume (unpainted zinc-aluminium steel) is used in applications where it will be concealed or where the natural silver finish is acceptable. Both have excellent corrosion resistance and long service lives in the coastal NSW environment.
Lead
Lead flashing has been used in building construction for centuries and is still specified in some situations — particularly around chimneys, parapets, and complex junctions where its malleability allows it to be formed into intricate shapes that sheet metal can’t replicate. Lead flashings are extremely durable and self-sealing. However, lead is less commonly specified in new residential construction today, partly due to environmental considerations and partly because modern metal alternatives perform well in most applications.
Aluminium
Aluminium flashings are lightweight, corrosion-resistant, and easy to work. They’re a strong choice for coastal environments where salt air is an issue, and are commonly used for penetration flashings and valley linings.
Copper
Copper flashings are long-lasting and self-healing (copper forms a protective patina over time), but they’re expensive and generally reserved for heritage or high-specification applications. Copper and steel should not be in direct contact, as galvanic corrosion can occur.
Flexible Membrane Products
In some applications — particularly at penetrations on flat or low-pitch roofs — flexible flashing membranes (typically bitumen-based or synthetic rubber) are used either alone or in conjunction with metal flashings. These are especially useful for forming watertight seals around irregular shapes where sheet metal is difficult to work.
New Flashing Installation Process
Site Assessment
Before any flashing work begins, we assess the location, the roof covering type, the junction geometry, and the water flow patterns that the flashing needs to manage. Good flashing installation starts with understanding how water moves across the specific roof section involved.
Material Selection and Fabrication
We select the appropriate flashing material for the application and fabricate custom pieces where required. Factory-cut or straight flashings are fine for some applications, but complex junctions typically require custom-fabricated pieces formed to the specific geometry of the installation.
Integration with Roof Covering
This is the critical step. Flashings need to be integrated with the roof covering so that water can’t enter at the transition between the flashing and the tile, sheet, or membrane. On tiled roofs, this typically involves lifting tiles, sliding the flashing into position under the tile lap, and bedding or fixing as required. On metal roofing, flashings are typically sealed with roofing-grade sealant and/or screwed at appropriate intervals.
Sealing and Fixing
All edges, laps, and ends of flashings are sealed with appropriate roofing sealant. On wall flashings, the top edge is typically embedded into a masonry joint or sealed with a strip seal product. All fixings are stainless steel or Colorbond compatible to avoid galvanic corrosion.
Testing
After installation, we run water over the new flashings to test for leaks and confirm that all transition points are performing as intended.
Why Choose Roof Restoration Coffs Harbour
- 25 years of local experience — we know exactly what Coffs Harbour weather demands from roof flashings.
- Licensed and insured — all roofing work by qualified, licensed tradespeople.
- Free inspections — no charge to assess and recommend.
- 10-year warranty — all new flashing installation is backed by our 10-year workmanship warranty.
- Custom fabrication — we form flashings to the specific geometry of your roof, not just fit a standard product and hope it seals.
Book a Free Flashing Assessment
Installing new flashings as part of a roofing project, adding a penetration, or extending your roof? Talk to us before the work starts to ensure flashings are properly planned and specified.
Call Nathan and the team at Roof Restoration Coffs Harbour on (02) 6638 9959. If you have existing flashings that are deteriorating, visit our flashing replacement page for specific information on replacing failed flashings. See our full range of services at our services page.
Properly installed flashings are what make your roof genuinely weatherproof. Call (02) 6638 9959 to discuss your flashing needs.
Flashings and Building Compliance
Flashing installation is subject to the requirements of the National Construction Code and relevant Australian Standards. For licensed roofing contractors carrying out work in NSW, ensuring that flashings meet these requirements is part of professional practice — not an optional extra. This matters for homeowners because non-compliant flashing installation can affect your insurance coverage and may cause problems if and when the property is sold and a building inspection is carried out.
When we install flashings, we do so to the standard required for compliant construction in NSW. We can provide documentation of the work carried out as part of any formal building project where required.
New Roof Additions and Flashing Planning
If you’re adding to your home — a deck with a lean-to roof, an extension, a new verandah, or a carport — flashing planning needs to happen at the design stage, not as an afterthought when the structure is framed and the question of waterproofing becomes urgent. We’re happy to consult at the planning stage on flashing requirements for new work, which avoids the costly scenario of incorrect flashing details being built into a structure that then needs to be partially deconstructed to fix.
Call us early in your project to discuss what the roofline junctions will require. A conversation at the design stage costs nothing and can prevent significant problems during and after construction.
Combining Flashing and Roof Restoration Work
New flashing installation is often part of a broader roof restoration or repair project — a roof restoration that involves recapping the ridge will also include checking and replacing valley and wall flashings. If you’re planning any roof work, discuss flashing needs as part of the overall scope. Addressing all required flashing work in one visit is more efficient and ensures the whole roof system is properly waterproofed when the project is complete.