If the coil is located on the back of the zipper instead of the front it is an Invisible Zipper. Metal zippers consist of individual metal teeth. They are typically made from nickel, brass, aluminum and manganese.
Repair costs generally range from about $2000.00 to $4500.00 per flue or more! In a Real Estate transaction, you may have the opportunity to negotiate defects that are disclosed as part of the inspection process.
1 A chimney inspection an assessment of how close you are to needing a cleaning and whether your chimney needs repairs might cost $45 to $85.