frannie - plenty of surplus material in the woods! i usually order extra for each project and the driveway down to the barn is lined with stacks of this and that

naturally, after a couple of years the stuff is covered in pine tags and i had no idea the slate was there! i do know i got about 15 cubes of bricks - i ordered a few extras and the contractor miscalculated badly when we added on back in the 90s
yup, and possibly lay it, too! nothing special required for that project - slate gets placed in the dirt, a la stepping stones