Ok I'm in need of some info I am trying to figure out how to install my woodstove and using the existing brick chimney but the chimney was knocked down in the attic when the new roof was put on the house. So my question is can i take stainless flex liner and run it in the chimney the put the flashing end cap on the top of the chimney and then run triple wall out of the roof there is a gap between my roof and the chimney approximately 18in. Would it be to much heat or would it not work at all or hopefully it will work great? Any advise appreciated first timer here pictures of chimney in the attic and a not so good drawing