Chimney Flashing Repair Cost (2026): Reseal vs. Reflash

How chimney flashing works

A chimney punches a big hole through the roof, and flashing is what keeps water out of the gap. It's two layers of metal that overlap.

Step flashing is a series of small L-shaped pieces woven in with each course of shingles up the sides of the chimney. Each piece laps over the one below it, so water steps down and out onto the roof. Counter flashing (also called cap flashing) is set into a cut groove in the mortar joints of the brick and folds down over the step flashing. The two layers can slide past each other, so the house and the chimney can move a little without tearing the seal.

At the front (downhill side) there's an apron piece, and at the back (uphill side) a back pan or a cricket. A roof leaking around chimney flashing almost always fails at one of three spots: the back corner, where water and debris pile up; a counter flashing that's pulled out of its mortar groove; or old work that was only ever caulked, with no step flashing at all.

For how to confirm that the chimney is really your leak, see the chimney flashing leak guide. It has a step-by-step checker and attic tests. This page covers what the fix costs.

Reseal, partial repair or full reflash

Reseal ($200 to $500). The roofer scrapes out cracked sealant along the counter flashing and corners and lays fresh polyurethane or butyl sealant. It works when the metal is intact and only the sealant has failed. Expect a few years, not a decade.

Partial repair ($300 to $850). Replacing a rusted apron, resetting counter flashing that has pulled out of the mortar, or rebuilding just the back corner. Shingles around the area are lifted and replaced. This is the most common chimney flashing repair.

Full reflash ($500 to $1,800). All step, counter and apron flashing comes off, the roofer cuts new grooves (reglets) in the mortar, and new metal goes on with fresh underlayment and ice-and-water membrane around the base. On a typical shingle roof this is a half-day to full-day job. It's the right call when the metal is rusted, the step flashing is missing, or the chimney was flashed with roofing cement alone.

If you're replacing the roof, the chimney should be reflashed as part of that job. Ask that it's written into the quote. See roof replacement cost.

Do you need a cricket?

A cricket, or saddle, is a small peaked roof built on the uphill side of the chimney. It splits water and snow around the chimney instead of letting it dam up against the back wall. The International Residential Code calls for one on chimneys wider than 30 inches measured across the roof slope, unless the back is flashed in a way the code allows. Plenty of older houses with wide chimneys don't have one, and those back corners leak again and again.

Adding a cricket during a reflash usually costs $500 to $1,500 on a shingle roof. It's framed in wood, sheathed, covered in membrane and shingled or covered in metal. On tile, slate or metal roofs, expect more. If your chimney is over 30 inches wide and you're paying for a full reflash anyway, a cricket is the most effective dollars in the job.

When the leak isn't the flashing

Brick is porous. Water can soak through a chimney above the roof, run down inside, and show up exactly where a flashing leak would. Before you pay for chimney lead flashing repair or a full reflash, have the roofer or a chimney sweep check the rest of the chimney.

• Cracked or missing mortar: repointing the area around the flashing costs $200 to $600. Repointing an entire chimney stack is a bigger job, often $1,000 to $3,500.
• Cracked crown: sealing runs $150 to $600, rebuilding $600 to $2,500.
• No chimney cap: rain falls straight down the flue. A cap is $150 to $500 installed.
• Soaking brick: a breathable masonry water repellent is often a few hundred dollars applied.

A good roofer will tell you if the flashing looks fine and point you to the masonry. Be wary of one who wants to reflash a chimney that has obvious crown cracks and no cap.

Worked example

A two-story house has a 36-inch-wide brick chimney on a 7/12 asphalt shingle roof. The original aluminum step flashing is corroded and there's no cricket, so the back corner leaks every spring. A roofer quotes:

• Full reflash with new step, counter and apron flashing: $1,300
• New cricket on the uphill side: $800
• Repoint mortar joints where the new counter flashing is set: $350
• Replace one sheet of rotted decking: $150

Total: $1,300 + $800 + $350 + $150 = $2,600. Resealing alone would have cost about $350, but with corroded metal and a 36-inch chimney with no cricket, it would likely have leaked again within a season or two.

DIY sealant vs hiring a roofer

If you have a single-story house with a walkable roof, the metal is in good shape, and the only problem is cracked caulk along the top of the counter flashing, a DIY reseal is reasonable. A tube of polyurethane or butyl roof sealant and a wire brush cost $15 to $50. Clean and dry the joint completely, then run a continuous bead. Don't smear roofing tar over shingles and metal. It traps water and makes the eventual proper repair harder.

Leave it to a roofer if the roof is steep, wet or more than one story, if the metal is rusted or missing, or if there's no step flashing under the shingles. Replacing step flashing means lifting and reweaving shingles, which is easy to get wrong.

Signs, insurance and ways to save

Signs of failing chimney flashing: stains on the ceiling or wall next to the chimney, damp framing around the chimney in the attic, leaks that show up mainly in wind-driven rain, rust streaks on the brick, and visible gaps or lifted metal. Ceiling stains alone can come from several sources, so see water stain on ceiling if you're not sure.

Insurance: Flashing torn off by wind or a falling branch is usually covered as storm damage, minus your deductible. Worn sealant, rust and age are treated as maintenance. Interior water damage may be covered if the leak was sudden. Photograph the damage before repairs. See storm damage roof repair for how claims work.

Ways to save:

• Fix it early. A $400 repair now beats rotted decking and a ceiling repair later.
• Combine the flashing job with crown, cap and repointing work in one visit.
• Reflash when you reroof, since the shingles are off anyway.
• Get 2 or 3 quotes and compare them with the quote checker.