Head-of-wall fireblocks and related wall assemblies

A head-of-wall fireblock device in combination with a dynamic head-of-wall assembly, comprising:

• an elongated sheet-metal header attached to a ceiling;
• a plurality of sheet-metal studs having upper and lower ends, the studs being vertically positioned relative to the ceiling and such that the upper ends are engaged within the header and proximate to a bottom interior surface of the header, each of the upper ends of the plurality of studs being spaced apart from the bottom interior surface of the header a first gap distance that allows for ceiling deflections;
• wallboard attached to at least one side of the plurality of studs, the wallboard being positioned apart from the ceiling a second gap distance that is about equal to the first gap distance;
• an elongated angled channel member attached to the ceiling, the header, or the ceiling and the header, the angled channel member being defined by an elongated top flange member connected to an elongated side flange member along a lengthwise edge, the top and side flange members defining a right angle and a lengthwise interior corner region, the top and side flange members each have inner flange member surfaces that face inwardly with respect to the interior corner region, and outer flange member surfaces that face outwardly with respect to the interior corner region, and
• an intumescent material strip affixed on the outer flange member surface of the side flange member and positioned immediately adjacent to the second gap.