US Patent 7812253 Fire resistant barrier

A fire resistant assembly, which may comprise a first layer having a lumen therein, a second layer adjacent the first layer, a first structural member disposed between the first and second layers, and a box having a cavity defined by a wall, a first opening in the wall, a flange proximate the first opening, and optionally a second opening in the wall, wherein the box is disposed between the first layer and the second layer and wherein the opening is disposed on the lumen of the first layer, the box comprising a further fire resistant feature such as an intumescent ring disposed about the second opening, a plenum wrap layer, or an intumescent layer, and various methods and apparatuses related thereto.