different roof flashing types

Roof flashings might not be the most visible part of a roof, but they are one of the most important. Get the flashing wrong and you will almost certainly end up with leaks and water damage. Choosing the right roof flashing comes down to understanding your roof type, how water moves across it, and what conditions the building will face.

Below is a practical breakdown to help you select the right flashings for different roof types and situations.

Start with the roof material

The first step is matching the flashing material to the roof itself. Mixing incompatible materials is one of the most common causes of premature corrosion.

Metal roofs

For metal roofing, flashings should generally be made from the same or a compatible material as the roof sheets.

Best options include:

  • Colorbond steel flashings for Colorbond roofs
  • Zincalume flashings for Zincalume roofs
  • This helps prevent galvanic corrosion and ensures performance while matching appearance.

Tiled roofs

Tile roofs rely heavily on flashings to direct water away from vulnerable points.

Common flashing choices:

  • Lead or lead-free flashings for chimneys and wall junctions
  • Custom metal flashings for valleys

Flexibility is important with tiled roofs, as tiles are not watertight on their own.

View all our metal roof flashings here.

Match flashings to roof pitch

Roof pitch plays a major role in how water flows and how much overlap is required.

  • Low-pitch roofs need wider flashings and greater overlaps to prevent water tracking back under the roof sheets.
  • Steeper roofs still require proper flashings, but water runoff is faster, reducing pooling risks.

If you are working on a low-pitch metal roof, choosing the correct apron, barge, and valley flashings is critical.

Choose flashings based on roof penetrations

Any penetration through the roof is a potential leak point and must be properly flashed.

Common penetration flashings include:

  • Apron flashings for walls and parapets
  • Back flashings behind chimneys
  • Pipe and vent flashings
  • Skylight flashings

For metal roofs, custom folded flashings often perform better than off-the-shelf options, especially around complex penetrations.

Consider environmental conditions

Australian conditions vary widely, and flashings need to suit the environment.

Coastal areas

In coastal or high-salt environments:

  • Use corrosion-resistant materials
  • Avoid mixing metals
  • Ensure protective coatings are intact

Bushfire areas

In bushfire zones:

  • Non-combustible metal flashings are essential
  • Gaps must be sealed to reduce ember entry
  • Flashings should comply with local bushfire requirements

Use custom flashings where needed

While standard flashings work for many applications, custom flashings are often the better option.

Custom flashings are ideal when:

  • Roof geometry is complex
  • Wall heights or roof angles are non-standard
  • A tighter, more weatherproof finish is required

Custom folded flashings reduce joins, improve water control, and often speed up installation on site.

Don’t forget fixings and sealing

Even the right flashing will fail if it’s not installed correctly. Good installation practices are just as important as choosing the flashing itself.

Make sure:

  • Fixings are suitable for the flashing material
  • Fasteners are spaced correctly
  • Sealants are compatible and UV resistant
  • Overlaps are sufficient for the roof pitch
     

Final tip

If you are unsure, always select flashings designed specifically for your roof type and conditions, or have them custom made. The cost of proper flashings is minor compared to the potential water damage and saves you headaches for years to come.

If you have any questions, reach out our sales team and we’ll guide you in deciding which flashing is best for your roof.

Contact: (08) 9399 3276

Source: https://www.yourhome.gov.au/buy-build-renovate/repairs-and-maintenance