I live in a 170 year old, Federal period house. I need to consider replacing the chimneys, which have been coated with cement to make them last a little longer. A brick mason has expressed concern that if the mortar is bad up top (the chimney in the back is leaning 6-8" toward neighbor's house which is 4' away) the mortar throughout the entire chimney structure will be similarly crumbling. (He did acknowldge that the mortar on the front and sides appear to be original - you can see bits of oyster shell - and not in need of replacement.)

Is it possible to replace just the chimney above the roofline and not worry about it being put on top of crumbling mortar for the 4 stories below? If my attachement comes through, you'll see that I have a basement, attic and 2 stories (I count that as 4 stories).

Sorry, could not attach the image. Kept getting an "invaalid image" message inspite of saving in .jpg and .tif