So I bit the bullet and went with the double wall metalbestis pipe. I have 1 question to pose and would love to hear your feedback as to the solution. My install is going to be a straight run from a T6 up through a cathedral ceiling. I am using the metalbestis telescoping pipe from the stove to the ceiling and it is where the telescoping pipe connects to the Cathedral "thimble" that I have my question. From my drywall out to my shingles is about 22.5 inches. There are 2 sets of rafters. One for the roof, and one for the ceiling. I have a metal plate to cover off on the inside. My telescoping pipe says that it requires 6 inches of clearance and my thimble requires 2 inches. Is is possible to extend the telescoping connection through the ceiling for the 4.5 inches that the thimble is short of, as long as I have 6 inches or greater clearance to all rafters/joists and drywall? (I guess it is possible, so the real question is would there be a concern doing so....) Or do they make a thimble that is 24 inches long vs. 18. Or do I need to get a 12 inch chimney section to put on the bottom of the thimble that I then have to paint black to match the inside?