Flashing Calculator
Calculate the total flashing length, width, and material area needed for roof perimeters and wall junctions.
How to Use the Flashing Calculator
- Enter the total perimeter length requiring flashing in metres.
- Enter the joint overlap in mm.
- Select the flashing material.
- Click Calculate to see total length and material area.
Casos de Uso
- •Estimating flashing material for roof edge and ridge details.
- •Planning flashing around skylights, chimneys, and penetrations.
- •Cost estimation for roofing projects.
- •Compliance with weathertightness standards.
Fórmula
Total length = Perimeter + (joints × overlap). Material area = Total length × Flashing width.
Preguntas Frecuentes
What overlap is recommended for flashing?
A minimum 150 mm lap is standard for most metal flashing materials to ensure weathertightness.
Which metal is best for flashing?
Copper is the most durable; zinc and aluminium offer good corrosion resistance at lower cost; lead is traditional but heavy.
Is it free?
Yes, all calculators on OhMyCalc are completely free.