Method sheet
Roof Edge, Coping, Fascia & Perimeter Quantities
Ordered edge runs with inside/outside corners and terminations: true lengths, straight pieces, corners, joints, end caps and cleat length.
Method
roof-edge 1.2
Engine
1.1.0
Output status
Informational
Review
Awaiting review
Formulas
- True length from plan = plan length x sqrt(1 + (rise / 12)^2)
- Net straight = true length - corner leg at each cornered end
- Pieces = 1 + ceil((net - L) / (L - lap)) when net > L
- Joints = (pieces - 1) per run + one at each cornered end of a run with straight pieces; two corners meeting directly share one joint
- Corner pieces are taken off at 2 x corner leg of material each; end caps go to the shop as counted items
Conventions
- Corner types and terminations are entered, never inferred.
Limits - what it will not do
- Geometry only: no wind performance is implied by a quantity.
- Corner pieces are counted, not designed.
Who must review it
- AFS estimator: corner piece leg lengths and splice practice
Worked example
Inputs 100 x 50 ft closed parapet, 4 outside corners, 2 ft corner legs, 10 ft pieces, no lap
Expected 30 straight pieces (26 x 10 ft + 4 x 6 ft), 34 joints, 300 ft
Checked by an automated test on every change.
Sources
- AFS fabrication limits - Architectural Flashing Supply, read 2026-10-15
Shop limits confirmed by AFS: max piece 10 ft 6 in, max girth 48 in, end flange 1/2 in, leg between bends 3/4 in, hem 3/8 in; material and gauge bend rules.