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.
The cost to rebuild the chimney above the exterior roof line is around $150 per linear foot. When it is simply a matter of repointing (repairing mortar 4 and loose bricks) the cost is around $25 per row.