Chimney & Flashing Repair

The Number One Leak Source on Any Roof

Flashing failures cause more roof leaks than any other single problem. Flashing is the metal — or sometimes membrane — that seals the joints where the roof meets a vertical surface: chimneys, walls, skylights, and vent pipes. Every one of these transitions is a potential leak point because two different planes of roofing meet at an angle, and the sealant and metal work together to keep water from entering the gap. When the sealant dries out, the metal corrodes, or the step flashing shifts, water finds its way in.

We repair and replace flashing at chimneys, walls, skylights, vent pipes, and valleys. Our crews fabricate custom flashing on site from copper, lead-coated copper, galvanized steel, or aluminum — matched to the roofing material and built to last.

How Chimney Flashing Works

Chimney flashing is a multi-component system, not a single piece of metal.

• Step flashing — L-shaped pieces installed one at a time, woven into the shingle courses along the sides of the chimney; each piece overlaps the one below it
• Counter flashing — embedded into the chimney mortar joints or reglet and folded down over the step flashing; this is the waterproof seal at the chimney face
• Base flashing — a wide piece that goes under the shingles at the front of the chimney and extends up the face
• Cricket or saddle — a small peaked structure behind the chimney that diverts water around it; required on chimneys wider than 30 inches
• Sealant — used at the counter flashing to chimney joint, not as the primary water barrier

The most common failure is at the counter flashing — when the sealant dries out and cracks, water runs down the chimney face and behind the step flashing.

Types of Flashing Repairs

Problem	Repair method
Dried sealant at counter flashing	Remove old sealant, re-seal with high-quality polyurethane
Lifted or separated step flashing	Remove affected shingles, re-install step flashing, re-shingle
Corroded metal flashing	Replace with new material matching the roofing system
Missing cricket on wide chimney	Build and install a cricket with proper flashing
Pipe boot failure	Replace rubber boot and collar with new UV-resistant unit
Wall flashing separation	Re-install step and counter flashing with proper sealant
Valley flashing damage	Remove old valley metal, install new valley flashing with ice-and-water shield

Flashing Repair Costs

Repair type	Typical range
Re-seal counter flashing	$200 – $500
Step flashing replacement (per chimney side)	$300 – $800
Full chimney flashing replacement	$1,000 – $2,500
Cricket installation	$1,500 – $3,500
Pipe boot replacement	$150 – $400
Wall flashing repair	$400 – $1,200
Valley flashing replacement	$800 – $2,000

Every flashing repair includes new sealant, properly fitted metal, and re-secured shingles. We do not just smear sealant over the problem and call it done.

Flashing Materials Compared

Material	Lifespan	Cost	Best for
Copper	50 – 80 years	High	Premium homes, long-term durability
Lead-coated copper	50 – 80 years	High	Traditional chimney flashing
Galvanized steel	15 – 25 years	Moderate	Budget-conscious, inland climates
Aluminum	20 – 30 years	Moderate	Coastal areas (no rust), residential
Stainless steel	50+ years	Very high	Industrial, chemical exposure

We match the flashing material to your roofing system. Copper pairs naturally with slate and cedar. Aluminum works well with asphalt shingles in coastal environments. Galvanized steel is the standard for most residential applications in inland areas.

Why Flashing Fails

• Sealant degradation — UV and temperature cycles dry out sealant joints within 10 to 15 years
• Metal corrosion — galvanized steel rusts in coastal and industrial environments; aluminum corrodes in contact with cedar tannins
• Settlement — building movement shifts the relationship between the chimney and the roof, breaking the flashing seal
• Ice and water backup — ice dams push water up under the flashing where gravity normally drains it away
• Poor original installation — flashing that was caulked instead of properly step-flashed will fail eventually
• Mortar deterioration — chimney mortar joints erode over time, loosening the counter flashing embedded in them

Preventing Flashing Problems

• Inspect flashing seals every two years — look for cracked or missing sealant at chimney and wall transitions
• Re-seal counter flashing joints before the sealant completely fails
• Replace corroded flashing proactively — do not wait for it to leak
• Ensure a cricket is installed on chimneys wider than 30 inches
• Replace pipe boot collars every 10 to 15 years — they are inexpensive and prevent a common leak source
• Repoint chimney mortar joints when they show signs of erosion
• Have flashing inspected as part of any roof replacement — if the roof is being replaced, flashing should be replaced too

Flashing Materials Compared

Material	Lifespan	Cost per linear foot	Best for
Aluminum	20 – 30 years	$5 – $10	Most residential applications
Galvanized steel	15 – 25 years	$4 – $8	Budget option, painted to match roof
Copper	50 – 80 years	$15 – $30	Premium, historic homes, visible areas
Lead	30 – 50 years	$8 – $15	Pipe boots and small penetrations

Aluminum is the most common chimney flashing material. It is lightweight, corrosion-resistant, and easy to form around irregular chimney shapes. Copper is the premium choice — it lasts longer than any other flashing material and develops a patina that complements slate and cedar roofs. We match the flashing material to your roof type, climate, and budget.

Common Chimney Flashing Failures

• Dried sealant — caulk at counter flashing joints shrinks and cracks over 5 to 10 years, allowing water entry
• Lifted step flashing — wind and thermal movement pull step flashing away from the chimney wall
• Missing cricket — chimneys wider than 30 inches without a cricket accumulate water and debris on the uphill side
• Rusted steel — galvanized steel flashing corrodes in coastal or industrial environments, creating pinhole leaks
• Improperly embedded counter flashing — counter flashing that was surface-mounted instead of grooved into mortar joints will pull out

Chimney leaking or flashing failing? Call us or request a free inspection — we will identify the exact failure point and repair it with properly fabricated and installed flashing.