We just moved into a cabin this fall with masonry chimney that has a tile liner. The top four feet of are very well bonded to the brick and I cannot bust them out with my drill powered "basher". So I am either going to tear the chimney down to below the roof line and run class A up from there, or tear the entire chimney down and relocate the new chimney so our stove can be against the front wall of the basement of the cabin instead of in the middle of it. However it is getting too late in the season for putting holes in our roof, so I am going save this project for summer, however we do still want to heat the basement, so I am planning on temporarily running the chimney out a basement window. If I replace the window with cement backer board can I run just single wall stovepipe for the entire course of the chimney, as long as I run my vertical stack 18" from the outside wall of the cabin?