Roof Flashings Explained for Wellington Homes

By the Metal Roofing Solutions team
Published 10 August 2026 · Wellington roofing guide

roof flashings are the shaped materials that help weatherproof the places where a roof changes direction, finishes at an edge, meets a wall or is interrupted by a skylight, flue or pipe. On a Wellington metal roof, those junctions deserve as much attention as the large roofing sheets.

A quote that names only the roof area and colour leaves important questions unanswered. The roof shape, catchment, profile, pitch, penetrations and adjacent materials determine which details are needed and how they should be formed.

What does a roof flashing do?

A flashing creates a controlled transition at an interruption or junction in the roof or wall envelope. It may cover the meeting point, direct water onto the roof surface, protect a cut edge or help prevent wind-driven rain from entering where two building elements meet.

Building Performance’s current E2/AS1 material contains specific sections for flashings, roof-to-wall junctions and profiled metal roof cladding. The NZ Metal Roof and Wall Cladding Code of Practice adds trade guidance for metal roofing, cladding, penetrations and accessories. These references need to be applied within their scope and alongside the selected manufacturer’s details.

Ridge and hip flashings

Ridges sit along the high meeting line of two roof planes. Hips run down an external angle. Both need adequate cover and support, and their ends and junctions need to work with the surrounding details. Wind exposure, profile shape and the roof design affect the final arrangement.

From the ground, homeowners usually see a clean folded cap. Underneath, the relationship between the capping and the profiled sheets is what helps manage wind-driven rain. That is why a close completion photograph can be useful even when the roof cannot be inspected safely by the owner.

Barges and roof edges

A barge flashing finishes the sloping edge of a gable. It is highly visible and exposed to the weather, so appearance and performance meet in the same detail. The selected profile, edge support and wind conditions all matter.

At the lower edge, the roofing, underlay, fascia and gutter also need a coordinated route for water. A quotation should identify whether existing gutters and edge flashings remain, are modified or are replaced as part of the roof work.

Skylights and other roof penetrations

A skylight creates an opening within the water path. Its size, location, the catchment above, roof pitch and roofing profile influence the suitable flashing method. Similar questions apply to flues, vents, ducts and pipe penetrations.

The NZMRM guidance notes that penetration design depends on factors including hole size and shape, pitch, roof type, catchment and placement. The responsibility for the skylight or penetration should therefore be clear: who checks the existing unit, who supplies any proprietary components, and what happens if concealed damage is found?

Roof-to-wall and change-of-pitch junctions

Where a roof meets a wall, an apron or related flashing arrangement directs water back onto the roof surface. Where the roof changes pitch or a lower roof connects to a taller section, water arriving from above must be considered in the design.

These areas are difficult to price from an aerial image alone. Photographs from several ground-level viewpoints and an on-site inspection help establish the actual junctions, access and existing conditions.

What should the quotation identify?

• the roof areas and junctions included;
• which existing flashings are removed, replaced or retained;
• the roof profile and proposed folded-metal details;
• skylights, flues, vents, pipes and other penetrations;
• gutters, valleys, parapets or roof-to-wall junctions;
• access, scaffolding and temporary weather protection;
• how concealed damage and variations will be handled;
• the documents and photographs supplied at completion.

Frequently asked questions

Can a leaking flashing simply be sealed?

Sometimes a local repair is appropriate, but sealant should not be used to disguise a failed shape, insufficient cover, movement problem or incompatible material. The cause and extent need to be assessed first.

Should all flashings be replaced during a re-roof?

The scope should be decided after inspection. Existing components need to be compatible with the new roof, suitable for their intended life and able to integrate with the proposed details.

Can a roofing quote be prepared from photos?

Photos are a useful starting point, but complex junctions normally require measurement and inspection. A safe ground-level photo cannot show every concealed or high-level condition.

Request a Wellington roofing assessment

If your roof contains several junctions, skylights or previous repairs, send us the property address and safe photographs from more than one side. We can then discuss the appropriate next step.

See our complex metal re-roof case study or Wellington metal roofing service.

Request a roofing quote or call 022 155 3184.