π How to Calculate Calamine / Roofing Sheets
Corrugated metal roofing (calamine) calculation requires accounting for lateral and longitudinal overlaps, sheet direction, and waste factor. This calculator ensures you order the exact amount of material needed for your roofing project.
π Sheet Calculation
Sheets across = Roof width Γ· Effective sheet width. Sheets along = Roof length Γ· (Sheet length - Longitudinal overlap). Total = Across Γ Along + waste.
π Overlap Calculation
Lateral overlap: 1.5 corrugations (β15cm). Longitudinal overlap: 15-20cm minimum. Steeper slopes allow less overlap; flatter roofs need more.
π© Fastener Calculation
Standard: 8 self-drilling roofing screws per mΒ² with neoprene washers. Place at every other corrugation crest on each purlin.
πΊ Ridge Cap & Accessories
Ridge caps: standard 2.44m with 10cm overlap. Also consider gutter flashing, wall flashing, and foam sealer strips.