Should roofers replace flashing?

Yes, roofers should absolutely replace flashing when replacing a roof, and replacement of all flashing should be considered standard practice for a quality roofing job. Flashing includes step flashing around chimneys, sidewalls, skylights, valley flashing, drip edge, and vent pipe boots, and it is the most critical component for preventing leaks at roof intersections and penetrations. Most roof leaks originate at flashing failures rather than in the field of shingles. Reusing old flashing to save money is considered poor workmanship and a common source of future leaks, as old flashing may have hidden rust, cracks, or improper installation, and its sealant is aged. When new shingles are installed, old flashing cannot be properly integrated with new shingles, leading to gaps. Professional roofing standards and manufacturer installation instructions from GAF, Owens Corning, and others require new flashing for full warranty coverage. A reputable roofer will include removal and replacement of all flashing in their written estimate, using quality materials like galvanized steel, aluminum, or copper that are compatible with the roofing system. Homeowners should explicitly ask if flashing replacement is included and verify it in the contract. If a roofer suggests reusing old flashing to lower the bid, that is a red flag indicating substandard work. Always insist on new flashing for a watertight, long-lasting roof.