First, build the frame for the thimble, making sure that it is no smaller than 14½” (368mm) diameter, which will maintain a 2” (50mm) air space around the chimney section. Attach the wall spacer to the chimney side of the frame. Then insert the frame into the opening, toe-nailing it to the wall studs. Install the wall band in the framing to secure the chimney section in place. Insert a single section of chimney connector into the chimney through the wall band, being sure it does not protrude into the chimney beyond the edge of the chimney flue lining. Apply high temperature furnace cement to the end of the chimney section and install it over the connector, through the wall band, and through the wall spacer. Tighten the wall band to hold the chimney section firmly in place and against the chimney. Install the trim collar on the outside of the opening. Check to insure there is a 1” (25mm) air space between the connector and the chimney section. Also, during installation, always check to insure that a 2” (50mm) air space is being maintained to the wood framing. Do not fill this space with insulation. Insulation in this air space will cause a heat buildup which may ignite the wood framing.
FIGURE 10
FIGURE 11