The concrete is broom finished. The builder used what he called "flume" or concrete sand to back fill. He says that it settles better than regular soil, and ours was clay soil. The concrete sand has small pea size gravel in it. The sand came from a local concrete company. I think the PB watered it in some, but no special packing equipment. He claims that if he packed it too much, the polymer walls of the pool could cave inward. (He cautioned us about getting to close to the pool edge before the deck was poured, because we could sink and cause the walls to cave in.) Anyway, he used 4" pvc pilings at every wall joint and they were suppose to be filled with concrete, when the deck was poured. He has a few other pilings spread around. I think they sit on the collar and support the deck. Surrounding area is level, but soil is clay gumbo type. Deck is 8' wide on one long side and deep end, and it is 4' to 6' (due to curved design)on the other long side and 10' at the shallow end.