Crown replacement costs $1,000 to $3,000. Cap repair costs $200 to $700. Chimney flue repair costs $250 to $1,000, and sealing and waterproofing leaks costs $150 to $400. A chimney stack that goes unrepaired for too long may have to be removed ( $800 to $2,000 ), rebuilt ( $1,000 to $3,500 ), or replaced ( $4,000 to $15,000 ).Web