Hi Hooksey,
Sand is the perfect material to use as it has very good drainage and in time turns into soil. If you ever look at Football Park (Aami Stadium) at West Lakes in South Australia, this stadium playing surface was totally built on sand and as such was known to be Australia's best playing surface, especially after rain as it took about 30 minutes and it was totally payable opposed to the MCG and many other major sporting venues. The secret is to do this around scarifying time when you get the surface back to base level, then just drag the leveller around and in a few weeks you'll have a perfectly flat lawn area.
Going back to what DeeJay has said, and that is you never put non living timber into the ground as its an open invitation to white ants and once they have been invited to the party they certainly know how to gate crash and trash a joint. Any pest controller will tell you that. Just ignore all that crap that the lifestyle shows on TV ram down our throats as they are after ratings and won't pay for the damages done to your home.
Cheers,
BB
