A fire resistant assembly, which may include 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 second opening in the wall, a panel having a panel opening fastened to the box about the second opening, and a fixture installed in the cavity and having conduit extending through the second opening and the panel opening.