Heatilator C40 Owner's Manual page 42

Chimney must extend
beyond combustible
roof structure
Maintain minimum
height of chimney
above roof
Install roof flashing
according to minimum
requirements
Offsets/returns
may not exceed
30° from vertical
Termination Cap
Additional
support for
tall chimneys
Storm Collar
Maintain minimum
clearances to
combustibles as
specified
Support straps for offsets/
returns must be secured
to adequate framing
Ceiling firestops
are required where
chimney passes
through ceiling or
floor