Expert: James Ball - 5/6/2009

Question
I'm interested in building a masonry chimney for my camp.  My metal pipe size (inside camp) is 8" and will be putting it through the wall with a tile thimble. Height of chimney will be approx 25ft.  I'm wondering whether I need an 8"x 8" flu or an 8"x 12" flu.

Answer
Hello Doug, I would check with your local building department. A 8" round has 50sq inches and a 8 X 8 has an inside of 7 X 7 of only 49sq. I would go with the 7 X11 they make a base flue with the horizontal hole in it you just have to mate it up and cement it in place, but you local building department will tell you what you need for that type of chimney construction.
James