All Roofing Calculators • Offline Access • Free Forever
Estimate materials + trim/flashing + fasteners + labor. Planning tool only — not a formal bid.
Results will appear here
Disclosure: This section contains affiliate links. As an Amazon Associate, we earn a small commission from qualifying purchases — helping us keep SmartRoofingCalculator free to use.
✅ Best Practices:
• Use step flashing where roof meets vertical walls.
• Counterflashing required for chimneys.
• Continuous valley flashing improves water shedding.
• Overlap flashing pieces at least 2–4 inches.
• Nail only at top edge to allow water runoff.
• Use corrosion-resistant metals (galvanized, aluminum, or copper).
• Seal all joints with roofing cement.
• Check code for required flashing around penetrations.
• Skylights and dormers demand custom flashing kits.
• Replace damaged flashing immediately — leaks spread fast.
Q: What is roof flashing?
Thin metal pieces installed to prevent water intrusion at joints, valleys, and penetrations.
Q: How much does roof flashing cost per linear foot?
Basic galvanized flashing runs ~$1–$2/lf, aluminum ~$2–$3/lf, and copper can be $5+/lf.
Q: Which material is best?
Aluminum is cost-effective, galvanized steel is durable, copper lasts longest but is expensive.
Q: How much overlap is needed?
Typically 2–4 inches (check manufacturer instructions).
Q: Do chimneys need special flashing?
Yes — use step + counterflashing for a watertight seal.
