14B-21-2113 Masonry chimneys.
The provisions of Section 2113 of IBC are adopted by reference with the following modifications:
1.   Delete the last sentence of Section 2113.3.
2.   Revise Section 2113.5 to read:
"2113.5 Corbeling.
Masonry chimneys shall not be corbeled more than half of the chimney’s wall thickness from a wall or foundation, nor shall a chimney be corbeled from a wall or foundation that is less than 12 inches (305 mm) in thickness unless it projects equally on each side of the wall, except that on the second story of a two-story building of Group R-5 occupancy, corbeling of chimneys on the exterior of the enclosing walls is permitted to equal the wall thickness. The projection of a single course shall not exceed one-half the unit height or one-third of the unit bed depth, whichever is less."
3.   Revise Section 2113.7 to read:
"2113.7 Offsets.
Where a masonry chimney is constructed with a fireclay flue liner surrounded by one wythe of masonry, the maximum offset shall be such that the centerline of the flue above the offset does not extend beyond the center of the chimney wall below the offset. Where the chimney offset is supported by masonry below the offset in accordance with accepted engineering practices, the maximum offset limitations shall not apply. Each individual corbeled masonry course of the offset shall not exceed the projection limitations specified in Section 2113.5."
4.   Revise Section 2113.11.1.4 to read:
"2113.11.1.4 Oil-fired appliances listed for use with L-vent.
Flue lining and vent systems for use in masonry chimneys with oil-fired appliances listed for use with Type L vent shall be limited to flue lining systems complying with Section 2113.11.1 and listed chimney liners complying with UL 641 (see Section 2113.11.1.5 for marking)."
5.   Revise Section 2113.11.2.2 by deleting "an approved."
6.   Revise Section 2113.11.3.2 by deleting "an approved."
7.   Revise Section 2113.11.3.4 by deleting "approved."