A cable management assembly that mounts cables to a ladder rack. The cable management assembly includes a thermal expansion block, a cable attachment beam, and a bracket. The thermal expansion block is positioned on a ladder rung of the ladder rack. The thermal expansion block has a top, a bottom, a first side, a second side, and ends. The first side and the second side of the thermal expansion block have an opening there through that receives the cable attachment beam. The bracket secures the thermal expansion block and attached cable attachment beam to the ladder rung.