Roofing Sheet Coverage Calculator

Corrugated Metal Sheets

Standard width: 26-36 inches (660-914 mm)
Coverage width: 24-34 inches (after lap)
Lengths: 6, 8, 10, 12, 14, 16 feet
Thickness: 26-29 gauge

Standing Seam Panels

Width: 12-18 inches
Coverage: 12-16 inches
Lengths: Custom cut to roof length
Thickness: 22-26 gauge

Corrugated Plastic/FRP

Width: 26-50 inches
Coverage: 24-48 inches
Lengths: 8, 10, 12, 16 feet
Thickness: 0.03-0.05 inches

Overlap Requirements

Side lap: 1-2 corrugations (2-4 inches)
End lap (low slope): 8-12 inches
End lap (steep): 4-6 inches
Sealant required for laps under 6/12 pitch

Example 1: Simple Gable Roof

Building: 30 ft × 40 ft
Roof pitch: 4/12
Sheet: 3 ft × 10 ft, 3 inch side lap
Effective width: 33 inches
Sheets per row: 40 ft / 2.75 ft = 15 sheets
Rows: 2 (both sides)
Total: 30 sheets

Example 2: Long Roof with End Lap

Roof length: 50 ft
Sheet length: 12 ft
End lap: 6 inches
Effective length: 11.5 ft
Sheets per column: 50 / 11.5 = 4.35
Round up: 5 sheets per column

Example 3: Hip Roof Calculation

Building: 40 ft × 40 ft square
Hip roof, 6/12 pitch
Roof area: 40 × 40 × 1.118 = 1,789 sq ft
Sheet coverage: 25 sq ft each
Sheets needed: 1,789 / 25 = 72 sheets
Add 10% waste: 79 sheets

Example 4: Metric Calculation

Roof: 10 m × 15 m
Sheet: 1 m × 3 m
Side lap: 80 mm
Effective width: 0.92 m
Sheets across: 10 / 0.92 = 11 sheets
Sheets down: 15 / 3 = 5 sheets
Total: 55 sheets