Abstract: The invention as shown herein demonstrates a prefabricated chimney which can be manufactured in sections of convenient length for handling and shipped to construction sites for venting boilers or the like. The chimney sections are of the multi-wall design whereby the inner tube conducts hot exhaust gases from a fuel-burning chamber to the outside. Tubes which are concentric or coaxial with the inner tubes insulate the building or other structural members from contacting the hot inner tube and insulating layer of air or otherwise retards the heat flow from the inner tube. The inner tubes of the sections are joined by a containment band which tightly engages the end flange of the inner tubes which may have rectangularly-shaped cross-sections.