Flashing Calculator

Calculate roof and wall flashing for chimneys, valleys, drip edges, and penetrations. Get total linear feet and metal area.

πŸ”© Flashing Calculator

Results

Total Flashing0.00 lin ft
Metal Area0.0 sq ft
10 ft Rolls0 rolls

πŸ’‘ How to Calculate Flashing Materials

Flashing prevents water intrusion at roof intersections, penetrations, and transitions. Add up all valley runs, step flashing along walls, chimney perimeters, and drip edge lengths. Typical flashing widths: 4–8 inches for step flashing, 12–18 inches for valleys.

Materials include aluminum (economical), galvanized steel (durable), copper (premium/long-lasting), and lead (chimneys). Step flashing pieces are typically 5Γ—7 inches, overlapping shingle-style. Valley flashing uses W-shaped or open metal.

A roof with 20 ft of valley, 16 ft of step flashing, 8 ft chimney perimeter, and 80 ft drip edge at 8-inch width: total = 124 lin ft of flashing = 83 sq ft of metal.

Flashing Calculator FAQ

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