2. THIMBLE:
An approved thimble must be used when the connection from the stove is made through a combustible wall to a masonry chimney. There are several methods you can use for connection through a combustible wall, two of which are illustrated in this manual. For additional methods, consult local build- ing authorities or use the standards set forth in NFPA 211.
Also, listed prefabricated metal thimbles are available for use with wood stoves. The manufacturer’s in- stallation for the thimbles must be strictly followed to assure the safety of the system. Be sure to maintain the designated clearances to combustible materials.
A. BRICK CHIMNEY THIMBLE
ASSEMBLY:
Construction of the brick thimble as- sembly requires 12" (305mm) of brick around a fire clay liner. Be sure the point of penetration allows an 18"
(457mm) clearance from the connector to the ceil- ing. For a 6" (152mm) chimney connector, an open- ing of 30" (762mm) must be cut in the wall to main- tain the required 12" (305mm) of brick separation from combustibles. It will be necessary to cut wall studs and install a header and sill frame to main- tain proper dimensions and to hold the weight of the brick (Figure 11).
Chimney
Wall
10
