A bin sorter for sorting lumber is provided. The bin sorter includes a plurality of bins disposed in a side-by-side configuration. Each bin includes a pair of spaced-apart walls defining a compartment therebetween for receiving lumber. Each compartment has a compartment inlet provided at a top end thereof, and a compartment outlet provided at a bottom end thereof. At least one of the plurality of bins has a support assembly for supporting one or more piles of lumber within the compartment. The support assembly includes a pair of support members having a support base vertically displaceable between the top and bottom ends of the compartment and a support arm connected to the support base and extending within the compartment towards the other support arm. Each support arm is adapted to support a respective pile of lumber or cooperate with one another to support a single pile of lumber.