What is the patio flooring going to be made of? Is wood involved? As in all things wooden, I'd be afraid of wood coming in contact with earth, even pressure treated wood; especially if the patio is going to be attached to a wooden house. Anyhow. My two cents. Wood+damp earth = rot and termites.

For a "detached" concrete or paver patio, the usual is packed earth, then gravel, then concrete. Best of luck!!

Ours is brick paver and raised approximately 8" at the edge furthest from the house. When I installed it, I excavated an additional 8" below the visable retaining wall, then filled with gravel (compacted) covered with about an inch of sand then the pavers. This provides good drainage and the settling has been very minimal in over 8 years. Personally, I can't imagine packed earth providing necessary drainage. And I agree with adknorth regarding any wood in contact with earth.

Photos of ours are linked from "My Page". Good luck.

Forrest

Thank you for the replies.
There is no wood involved with the project. Living in Michigan
we're all about deep footings and drainage, that's why
the 'packed earth' method sounded a little funny to me.