How much does it cost to replace flashing around a chimney or vent?

Flashing is the metal or rubber seal that bridges the gap between a roof and a chimney, vent, or skylight. Water exploits failed flashing relentlessly. Replacement costs vary by location, material, and size.

Simple rubber flashing around a single vent costs less than metal flashing around a large chimney that requires step flashing (multiple overlapping pieces). Labor intensity drives cost up significantly because the roofer must remove and reset shingles, apply sealant, and ensure the flashing locks water out permanently.

Material and lifespan

Aluminum flashing lasts longer than tar based alternatives and costs more upfront. Rubber flashing wears faster in sunlight but is cheaper initially. Ask contractors about material grade and expected lifespan so you're not replacing the same flashing in five years.

Warning signs

If water leaks appear inside near a chimney or vent, flashing failure is the first suspect. Rust stains around the flashing exterior or visible separation between flashing and roof surface are clear signs. Don't wait; leaking flashing spreads damage inside walls quickly. Get it inspected and replaced promptly to avoid the much larger repair bill that follows water intrusion.