New Buck Corporation 21 - Manual (Page 13)

C. Wall Exit Into Masonry (Using Single Wall Pipe)
1. Before connecting these units to a masonry chimney, determine that the masonry fireplace
wall pass-through connector thimble meets the NFPA-211 Code and local building codes
and is a minimum of 18" from the ceiling. If the connector thimble does not meet
these codes, the pass-through connector must be modified. (See Figure 9.)
Figure 8
CHIMNEY
Figure 9
PASS-THROUGH
CONNECTOR
11