Two-piece track system
A fire-rated receiver channel includes at least one intumescent or other fire-resistant material strip. The receiver channel can nest with a framing member, such as metal tracks, headers, header tracks, sill plates, bottom tracks, metal studs, wood studs or wall partitions, and placed at a perimeter of a wall assembly to create a fire block arrangement. In other arrangements, a track assembly includes two nested tracks, an inner track and outer track. The assembly is designed so that the outside width of the outer track is equal to or less than the outside width of the inner track to present a substantially flush external surface for attachment of exterior sheathing elements when the assembly is used in an external wall.
1. A two-piece fire-rated track assembly for a linear wall gap, comprising:
a first track that has a web, a first flange and a second flange, wherein the web is substantially planar and has a first side edge and a second side edge, the first flange and the second flange extend in the same direction from the first and second side edges, respectively, wherein each of the first and second flanges is substantially planar such that the first track defines a substantially U-shaped cross section having a maximum external width dimension;
a second track that has a web, a first flange and a second flange, wherein the web is substantially planar and has a first side edge and a second side edge, the first flange and the second flange extend in the same direction from the first and second side edges, respectively, wherein each of the first and second flanges is substantially planar such that the second track defines a substantially U-shaped cross section, each of the first and second flanges has a free end opposite a respective one of the first side edge and second side edge, wherein the first and second flanges of the second track define a minimum internal width that is greater than the maximum external width dimension of the first track;
at least one heat-expandable intumescent strip attached to the second track and extending lengthwise along a surface of the second track;
wherein, in use, the first track and the second track are aligned with one another in the same direction and the first track is nested within the second track.
2. The assembly of claim 1 , wherein the at least one intumescent strip extends along and is attached to a portion of the web of the second track such that the portion contacts an adjacent structure when the two-piece track assembly is assembled to the adjacent structure.
3. The assembly of claim 1 , wherein the at least one intumescent strip further comprises a portion that extends past an outer surface of the web of the second track.
4. The assembly of claim 2 , wherein the at least one intumescent strip defines a total length in a cross-sectional direction, wherein a portion of the total length located on the flange is at least three times greater than a portion of the total length on the web.
5. The assembly of claim 2 , wherein the at least one intumescent strip covers a substantial entirety of the outer surface of the flange.
6. The assembly of claim 2 , wherein the at least one intumescent strip comprises a first intumescent strip and a second intumescent strip on the first and second flanges, respectively.
7. The assembly of claim 1 , wherein the first and second flanges of the first track are longer than the first and second flanges of the second track.
8. The assembly of claim 7 , wherein the first and second flanges of the first track are at least twice as long as the first and second flanges of the second track.
9. The assembly of claim 1 , further comprising a plurality of slots on the first and second flanges of the first track, wherein the slots extend in a direction perpendicular to a length of the first track.
10. The assembly of claim 1 , wherein the first track is a footer or header track.
11. The assembly of claim 1 , wherein the first track is a metal stud.