Chimney Flashing — The #1 Source of Roof Leaks

In our 20 years on NYC rooftops, the single most common cause of roof leaks is failed chimney flashing. The chimney is a brick-and-mortar structure embedded in a roof made of completely different materials. The transition between them is where everything goes wrong — and where we specialize in making it right.

Common Problems We Solve

• Water stains in the room with the chimney
• Damp or wet brick around the chimney
• White efflorescence on the chimney bricks
• Visible gap between chimney and roof
• Old cement-only "flashing" (not real flashing)
• Cricket missing on the high side

Our Process

• Inspection of existing flashing & counter-flashing
• Tear-off of old flashing & cement
• Step flashing installed shingle-by-shingle
• New counter-flashing cut into the mortar joint
• Cricket installed on chimney high side (if missing)
• New cap flashing & sealants
• Optional crown rebuild & waterproofing

Materials We Use

Aluminum step flashing for asphalt shingle roofs. Lead and lead-coated copper for historic and brownstone work. Henry 555 or NPC Solar Seal sealants. Mortar-cut counter-flashing (not surface-mounted).

Frequently Asked Questions