UL-103:2010 pdf free download – STANDARD FOR SAFETY Factory-Built Chimneys for Residential Type and Building Heating Appliances.
14 Support Assembly
14.1 A support assembly (such as a ceiling or floor support) shall establish and maintain the minimum
required clearance between a chimney section and combustible construction. A support for installation in
a joist area shall constitute a complete firestop when tested in accordance with these requirements.
14.2 A support assembly shall sustain a load equivalent to four times the weight imposed upon it by all chimney parts it is intended to support. See Vertical Support Test, Section 26.
14.3 A support assembly intended to be secured by nails or screws shall be arranged so that the load on such holding means is a shear load.
14.4 A chimney assembly intended for exterior installation shall be provided with support assemblies. See Sections 26, Vertical Support Test, and 28, Wind Load Test.
14.5 An offset chimney section shall be supported at or immediately above the vertical return elbow at the first floor or roof above the offset section.
14.6 An exterior support assembly shall be constructed to maintain specified clearances to adjacent combustible construction.
15 Openings in Chimney Walls
15.1 Openings for airflow provided in the chimney’s walls shall not be located in the flue gas conduit wall. Such openings shall not impair the structural integrity of the chimney.
15.2 The openings for air flow specified in 15.1 shall be located within the chimney support assembly. Those openings made at chimney joints that are intended for fastening adjoining chimney sections together only are not air flow openings and are not required to be located within the chimney support assembly.
PERFORMANCE
16 General
16.1 When a chimney is tested in accordance with these requirements, specified temperatures on combustible construction shall be maintained.
16.2 After being subjected to the tests specified in Sections 19 — 23, as applicable, a chimney shall be capable of being used further.
16.3 Test results indicating compliance with the requirement of 16.2 include the following:
a) No part of the chimney has become damaged or permanently distorted to an extent that it or the chimney assembly does not continue to function as intended.
b) The effectiveness of any required protective coating or finish on metal parts has not been reduced.
c) A ceramic material shows no evidence of cracking, disintegration, or spalling to the extent that serviceability of any part of an assembly has been impaired.
d) Cracks are not observable in porcelain enamel used as a required protective coating when the surface is examined under a microscope of 60 magnification.
e) The reflectivity of a surface has not been impaired when the reflectivity is utilized to reduce the risk of fire.
f) Burning or scaling of metal parts is not evident upon visual observation.
Exception: Scaling of chimney flue liner material that does not impair the function of the chimney is permitted after exposure to the temperature test specified in Section 23.
g) The effectiveness of insulating material has not been reduced.
16.4 Thermal insulation shall comply with the following requirements during and following tests on the chimney:
a) The products resulting from the combustion or volatilization of any combustible binder shall be discharged to the chimney terminus outside of the building.
b) The insulating material shall remain in its intended position.
c) The thermal conductivity of the insulating material shall not be increased.
d) The thermal insulation shall not show evidence of softening, melting, or other evidence of malfunction or deterioration.
17 Test Installations
171 General
17.1 .1 The following factors are to form the basis of the performance tests of a factory-built chimney:
a) For a chimney intended to be enclosed by combustible construction.