A deck system is disclosed having a mounting plate with a planar support surface and at least one locating rod extending from the support surface. The locating rod extends in a direction that is substantially perpendicular to the support surface. A beam having a first end and a second end is positioned on the support surface of the mounting plate. The first and second ends of the beam have a slot and the slot is disposed for receiving the locating rod. At least one tread is disposed to extend between the two spaced apart parallel oriented beams. The tread has opposed shoulders on the side of the tread that engages the spaced apart beams. The opposed shoulders are disposed for engaging a side of the spaced apart beams that are in adjacent relationship.