I have a newer oil furnace that’s connected to the original coal furnace masonry chimney. the chimney has a 11 3/4″ x 6 1/4″ clay flue liner. I want to install a wood stove. Is it possible to install 2 stainless steel flue liners (a 5″ for my furnace and 6″ for the wood stove) in the old masonry chimney. I know in new chimney construction they want a 4″ wythe between flues, how important is that?
I plan to cover the whole chimney with a flue cap that allows the flues to discharge at differant heights.