Every roof face the engine drew is panelised on its own terms. Rectangular faces carry no cut waste; hipped triangles carry 15%; trapezoids carry 10%. Faces longer than the 40ft mill/trucking ceiling are split into equal segments and the line says so. Visual ridge and break laps the engine adds for interpenetration are subtracted — they are not extra steel.
Also called: roof panel count · how many roof sheets · roof waste · panel splice
- 1roofFaceArea drops the RIDGE_LAP / BREAK_LAP the renderer adds so laps are not billed
- 2Sheets per face = ceil(eave span ÷ coverage), then inflated by the waste percentage for that face shape
- 3Faces over MAX_PANEL_LEN (40ft) are split into segments and the quantity multiplied
- 4Groups are keyed by length and face kind, so a quote gets one row per real panel length
- 5Shingle roofs take a different path entirely: squares plus an OSB deck, because they are a different product bought in a different unit
A hip roof cut from rectangular sheets wastes materially more than a gable, and pretending otherwise short-orders the job. The shingle split carries its own warning: '⚠️ NOT "ExteriorRoof". Shingles are sold by the SQUARE (100 sq ft) and steel by the PANEL — the same usage carrying two units meant a square was priced as a panel.' The OSB line notes that the sheet must declare its 8ft 'or a per-foot rate bills it as one foot.'
- Cut waste on non-rectangular faces is invisible until the job is short
- A 50-foot slope cannot be supplied as one sheet
See it on your own jobs
Twenty minutes, your numbers, no slide deck. We’ll build one of your real buildings in front of you and send you the estimate link at the end — yours to keep either way.
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