A method and apparatus for creating firestopping barrier in a partition, such as a wall, floor, or ceiling, that is mounted adjacent the opening includes a housing containing a central opening. The cross-sectional area of the housing is greater than the cross-sectional area of the through-penetration opening, and the housing is arranged external to the through-penetration opening with at least a portion thereof extending along a surface of the partition thereby to allow the housing to be installed adjacent the through-penetration opening. Firestop material is arranged within the housing.