UL 103 2017 pdf download – Factory-Built Chimneys for Residential Type and Building Heating Appliances.
7 Assembly 7.1 A chimney shall consist of all the essential parts required for the intended installation of a complete chimney assembly. Each part of the assembly shall be constructed for ready attachment of one to the other without requiring alteration by the installer, such as by cutting, threading, drilling, welding, or similar tasks. Exception: An assembly or component part intended to be cut to length or to be fitted by the installer is provided when means are furnished for joining any altered part to a companion part or assembly. All fasteners required to complete the assembly shall be provided with the product by the manufacturer. Drilling shall not occur unless: a) The drilling operation does not weaken the assembly or penetrate into the flue liner; and b) The size ofthe required drill bit is specified and the instructions clearly describe the locations to be drilled, such as by the use ofdrawings, descriptions, or templates. 7.2 Two or more parts or subassemblies that bear a definite relationship to each other in the intended application shall: a) Be arranged and constructed to permit them to be incorporated into the complete assembly without alteration or alignment and only in the correct relationship with each other; or b) Be assembled and shipped from the factory as one unit. 7.3 Each part, such as a chimney-pipe section or length, cap, firestop-spacer, support element, roof assembly, or jack shall be completely assembled by the manufacturer at the factory. 7.4 To comply with the requirements of 7.3, a chimney-pipe section comprised of a flue-gas conveying conduit, formed insulation or other intermediate assembly, and an outer jacket, which are separable, shall be preassembled and packaged as one unit. A firestop-spacer assembly constructed in two halves shall be packaged as one unit. In such cases, each separable part shall be completely formed, including the joining of all seams.
8 Chimney Caps 8.1 A cap shall be provided. Exception: A chimneydesignatedas a building heating appliance type onlyandthatdoes notincorporate unprotected ventilation openings terminating exterior to the building is not required to be provided with a cap. 8.2 A cap shall resist the entrance of debris and rain into the flue gas conveying conduit and into any unprotected ventilation openings terminating exterior to the building. Protection devices intended to protect only ventilation air openings terminating exterior to the building shall resist the entrance of debris and rain into such ventilation openings. See Rain Test, Section 28. 8.3 A cap shall be constructed so that leaves and debris fallen or blown onto it are not retained so as to obstruct flue-gas or cooling-air passages. A cap shall be constructed to resist the accumulation of soot that will obstruct the flue-gas or cooling-air passages. 8.4 A cap shall be removable and replaceable by the use of simple hand tools (screwdriver, wrench, pliers, or similar tools) to allow for chimney cleaning in accordance with the installation and maintenance instructions without bending or deforming the chimney or parts thereof.