Abstract: An intumescable fire stop device that is easy to install and effectively and efficiency channels heat to an intumescent material so that the intumescent material expands quickly and uniformly includes a collar. An inner surface of the collar has a plurality of heat conducting tabs that extend outwardly and secure the intumescent material to the collar. The heat conducting tabs extend into the intumescent material and thereby effectively channel heat from a fire into the interior regions of the intumescent material so that the intumescent material expands quickly and uniformly. The collar further includes a first interlocking end having a plurality of spaced openings. The spaced openings are configured to receive spaced fingers on a second interlocking end of the collar. The interengagement of the fingers and openings allows the collar to be firmly secured about a section of a pipe. The collar has a plurality of releasibly secured Z-shaped mounting clips.