They have a 40 yard dumpster they put down by the road, but its all the scrap, even the stuff with nails in it coming back from jobs. The guy I know lets me know when there is a crap load of all similar size stuff. I drive right up in behind the building and load it. This time he had it all on a pallet for me, but no sides!
They heat the building with their scraps too. They had a boiler built that takes two pallets at a time, pallets, and all. They use the scrap plywood build sides on the palettes about 4' tall, load them up, and when the furnace needs to be filled they slide two palettes into it with a fork truck, or lull.