RICK Yes cinder block. My bench is outside the GH in what will be my fenced garden area eventually, right next to the GH. My 6 x 8 GH really has no room for a potting bench, unfortunately. But I have those brick pavers in the floor so with the bench outside I just brush the dirt off. Guess that's an advantage. I have a tall set of shelving in there and I can use a tray and do a little seed potting now and then. Our winter in central Texas is short so I will get by and sometimes we get some nice warm days even in winter. Until I bite the bullet and decide to expand the GH. Hubby already suggesting this!!
I did see a wonderful potting bench in utube that had a large pan that slides in the top to catch the dirt. Nice for in the GH if you have room.