Apply the answer
Use the roof details as measured quantities.
Keep roof area, roof lines and individual penetrations separate when you have plans or measurements.
The roof terms that matter most
| Term | What it means | Why it matters |
|---|---|---|
| Ridge | The high, usually horizontal line where two roof planes meet. | Needs a ridge flashing or capping and contributes lineal flashing quantity. Sources: NZ Metal Roofing Manufacturers; NZ Metal Roofing Manufacturers. |
| Hip | An external sloping junction where roof planes meet. | Usually receives hip flashing/capping and creates angled cuts in roof sheets or tiles. Sources: NZ Metal Roofing Manufacturers. |
| Valley | An internal junction between roof planes that collects and carries water. | It is part of the drainage path, so capacity, support and detailing matter. Sources: NZ Metal Roofing Manufacturers. |
| Barge / verge | The sloping edge at the side of a roof. NZ documents use both terms around the edge and its flashing. | Barge/verge flashing length is separate from roof area. Sources: NZ Metal Roofing Manufacturers; NZ Metal Roofing Manufacturers. |
| Eaves | The lower roof edge where water leaves the roof, often into external guttering/spouting. | Eaves length affects drainage, fascia/spouting and some flashing details. Sources: NZ Metal Roofing Manufacturers. |
| Fascia | A vertical board at the lower ends of rafters or trusses, commonly carrying external spouting/guttering. | It sits at the eaves edge and can be a separate repair/replacement scope from the roof cladding. Sources: NZ Metal Roofing Manufacturers. |
| Soffit | The enclosed underside of an exterior eave overhang. | It is below the roof edge rather than part of the roof covering, but staining or damage here can point to drainage or moisture issues. Sources: NZ Metal Roofing Manufacturers. |
| Purlin | A horizontal secondary structural member that supports roof cladding. | Purlin condition and spacing can affect fixing and reroof scope; it is not the same thing as a roofing sheet. Sources: NZ Metal Roofing Manufacturers. |
| Rafter | A sloping primary structural member running from ridge toward eave and supporting secondary members and roof cladding. | Rafters are framing; roof-covering quotes should not silently assume structural repairs are included. Sources: NZ Metal Roofing Manufacturers. |
| Apron flashing | Flashing where a roof meets a wall or another upstand. | It protects a change in plane that roof cladding alone cannot weatherproof. Sources: NZ Metal Roofing Manufacturers; NZ Metal Roofing Manufacturers. |
| Penetration | An opening through the roof for items such as pipes, ducts, chimneys or roof lights. | Each penetration needs its own compatible weathering detail. Sources: NZ Metal Roofing Manufacturers; NZ Metal Roofing Manufacturers. |
Which roof lines change quantities and difficulty?
Two roofs with the same square metres can have very different lineal quantities. A simple gable has a ridge and two sloping verge edges; a hip roof adds hips; intersecting roof sections add valleys. Those extra junctions create more flashing, cutting, detailing and opportunities for water to be concentrated. Sources: NZ Metal Roofing Manufacturers; NZ Metal Roofing Manufacturers.
- Keep roof area in square metres separate from ridge, hip, valley and barge lengths in metres.
- Record penetrations individually rather than hiding them inside a generic complexity percentage.
- When comparing quotes, check whether the named flashings and junctions are included, not merely the roofing sheets.
- If a term on a plan or quote is unclear, ask what physical roof junction it describes.
What is part of roof drainage?
NZMRM uses “gutter” as a broad term for channels that collect and carry roof water, while “spouting” refers specifically to an external gutter. Valleys, internal gutters, secret gutters and roof gutters around obstructions can all be part of the drainage system. Sources: NZ Metal Roofing Manufacturers.
That distinction matters because an external spouting replacement is not the same scope as an internal gutter or valley replacement. Internal drainage elements are more integrated with the building envelope and should be identified clearly in drawings and quotes. Sources: NZ Metal Roofing Manufacturers.
How should these terms appear in a roofing quote?
- Roof covering/profile and coating named separately.
- Ridge, hip, valley and barge/verge scope stated where relevant.
- Wall junctions and apron flashings identified.
- Penetrations such as flues, pipes, skylights or vents listed rather than assumed.
- Gutters/spouting and downpipes clearly included or excluded.
- Repairs to fascia, purlins, substrate or framing separated from the cladding scope.
A quote does not need to read like an engineering drawing, but it should be clear enough that two people can tell whether they are pricing the same roof system and the same junctions. Sources: Roofing Association of New Zealand.
Related questions
Is a barge the same as a verge?
In everyday NZ roofing usage they refer to the sloping roof edge, while specific documents may use “barge” for the flashing or assembly at that edge and “verge” for the edge itself. Check the drawing or quote context rather than assuming the word alone defines the component. Sources: NZ Metal Roofing Manufacturers; NZ Metal Roofing Manufacturers.
Is a valley a flashing or a gutter?
It is an internal roof junction that carries water. NZMRM drainage terminology treats valleys as roof-drainage channels, and the installed valley detail also performs a flashing/weathertightness function. Sources: NZ Metal Roofing Manufacturers; NZ Metal Roofing Manufacturers.
Do hips and valleys change roof area?
They describe the geometry and junctions of roof planes. They may correlate with a more complex shape, but their lineal lengths should not simply be converted into an arbitrary area multiplier.
Sources and review notes
Prepared by RoofHub editorial. Reviewed . A source check confirms what a page states, not an independent inspection or invoice audit. Published project accounts are attributed to their publishers.
- primaryNZ Metal Roofing Manufacturers: Code of Practice v26.09: Domestic cladding terminology - Current NZMRM domestic roofing nomenclature showing common terms including ridging, penetrations, underlay, valleys, barges, aprons, roof lights, gutters and downpipes. Used for NZ terminology, not as a complete design specification. Page checked 2026-10-21. Publication date not stated. · industry-technical
- primaryNZ Metal Roofing Manufacturers: Code of Practice v26.09: Flashings - Current MRM flashing guidance. Defines the purpose of flashings and identifies common types including ridge/hip, barge/verge, parapet cappings, apron and valley; penetration flashings are treated separately. Page checked 2026-10-21. Publication date not stated. · industry-technical
- primaryNZ Metal Roofing Manufacturers: Code of Practice v26.09: Roof drainage terminology - Current NZMRM terminology for external gutters/spouting, internal gutters, secret gutters, valleys and related roof-drainage terms. Page checked 2026-10-21. Publication date not stated. · industry-technical
- primaryNZ Metal Roofing Manufacturers: Code of Practice v26.09: Glossary definitions - Current NZMRM glossary definitions for common roofing terms including fascia board, eaves, soffit, purlin and rafter. Used for terminology rather than project-specific design. Page checked 2026-10-21. Publication date not stated. · industry-technical
- primaryNZ Metal Roofing Manufacturers: Code of Practice v26.09: Roof penetrations - Current NZMRM roof-penetration guidance. Penetration detailing depends on hole size and shape, roof pitch and type, catchment area, position and durability/compatibility requirements. Page checked 2026-10-21. Publication date not stated. · industry-technical
- primaryRoofing Association of New Zealand: RANZ Re-Roofing Guide - RANZ describes this as an annually updated NZ consumer guide to reroofing materials, systems, terminology, scope and workmanship. Used for project-planning context rather than contractor ranking. Page checked 2026-10-21. Publication date not stated. · industry-technical
Original calculations are labelled as examples. Historical prices stay dated, missing fields stay unknown, and conflicting specifications are flagged. Sources are not endorsements or paid rankings. Read our methodology or report a correction.
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