Flue liner for masonry chimneys
Flue liners do just that...they are a new flexible pipe that lines the length of the chimney sealing the cavity. They also include a flashing that sits on top of the crock sealing the chimney at the top and a new chimney cap to keep animals and the weather out. The liner extends from the new cap on top and comes out of the chimney typically in the basement and ties into the furnace and/or the hot water tank. In addition to encapsulating the flue gases the liner reduces the size of the chimney cavity to provide a proper draft
http://www.hartandcooley.com/Libraries/Product_Literature/Brochure_-_Flexible_Aluminum_Chimney_Liners.sflb.ashx
Starting at $350 installed