Abstract: An bi-directional mounting bracket assembly is utilized in conjunction with exterior siding that covers sheathing of an exterior wall. A base member of the assembly has a mounting flange secured to the sheathing and a wall arrangement that projects outward with respect to the sheathing and from the mounting flange. Preferably, the wall arrangement supports a raised central panel used for mounting of fixtures. The wall arrangement preferably has four walls extending laterally between the mounting flange and the central panel. Spaced radially outward from the two adjacent walls are respective first and second drip ledges, and spaced radially outward from the other two adjacent walls are respective first and second baffle sets. When the assembly is mounted to the sheathing, a selective one of the two drip ledges is disposed substantially horizontally and beneath the wall arrangement for shedding of water.