A named longrun profile is a cover width, a minimum cladding pitch, a run-length check, and a fixing pattern. Appearance comes after those four. Count sheets from effective cover after the side lap, never from overall blank width. The library on NZ Roof Tools is the set below; always confirm the current product sheet.
The four numbers
- Cover — laid width after the lap (762 mm Dimond corrugate, not 851 mm overall).
- Sheet length — slope including eaves, usually one sheet ridge-to-eave.
- Cladding pitch — CoP / manufacturer table after deflection, not the degrees on the truss ticket.
- Check-run — CoP “check capacity after …” length for that rib height.
Using overall width on a 12.1 m ridge of 762 mm corrugate under-orders by about a sheet per plane. The sheet calculator and longrun calculator count from cover.
Families in this takeoff
Corrugate (16.5 mm rib). CoP 7.1.1A: 8° minimum, check after 15 m. Dimond 762 mm cover; Metalcraft and Stratco CGI commonly 760 mm. Metalcraft also publishes 9° once sheets go past 30 m (≤100 mm/hr). A 6° garage is outside this row — corrugated calculator and min pitch.
Shallower trapezoidal (Six Rib, ~20 mm). 4° / 20 m, cover about 760 mm. The usual step down when corrugate fails min pitch. Trapezoidal calculator.
Deeper five-rib (Hi Five, T-Rib, ~27 mm). 3° / 40 m. Dimond Hi Five cover 765 mm (some sheets 755 mm); Metalcraft T-Rib 760 mm. Same CoP row, different rolls — do not mix on one roof. Hi Five on a low-pitch job.
Tray / secret-fix. Narrow pans, typically 3°, clip fix. The library includes a generic 300 mm tray so you can see the CoP row; override cover if you know the pan. Geometry is not corrugate.
Two profiles that look similar can differ by 5 mm of cover, a degree of pitch, and 20 m of allowable run. Put the data-sheet name on the takeoff.
Flashings, waste, wind
Ridge, barge, hip, valley and apron are lineal metres. Extra High wind zone forces Category B flashing covers at every pitch. Hips and valleys need cutting waste; a clean gable is mostly per-plane round-up. Waste calculator.
NZMRM CoP v26.09 (1 September 2026) updated flashing expansion, gutter, valley freeboard and hip details. Use the current table, not last year’s printout.
Order checklist
- Name manufacturer + profile, not “longrun iron”.
- Write cover in millimetres from the coil or current sheet.
- Check cladding pitch and run length against that row.
- Split planes; do not average a house and a 4° lean-to.
- List flashings and shape-based waste separately.
- Confirm colour, BMT, max cut length and (for Hi Five) which island can supply it.
Open the takeoff, pick the named profile, and read the warnings before anyone cuts coil. Product sheets and the NZMRM Code of Practice still win.