A mechanical header is provided for spanning a corridor in a building and for hanging mechanical equipment therefrom. The mechanical header includes a first angle member comprising a first horizontal portion and a first vertical portion, where the first horizontal portion extends away from the first vertical portion in a first direction. The mechanical header further includes a second angle member comprising a second horizontal portion and a second vertical portion, where the second horizontal portion extends away from the second vertical portion in a direction opposite the first direction. A spanning beam is coupled to the first vertical member and to the second vertical member. The first horizontal portion is configured to rest on top of a first wall structure, and the second horizontal portion is configured to rest on top of a second wall structure, such that spanning beam spans the corridor and hangs just at or below the level of the top of the first and second wall structures.