Playground Footing - Gravel or Dirt beneath the structure - Sunray Premium Playground from CostCo?

I'm building a Sunray Premium Playground from CostCo. I have cleared out a 30' x 30' area as instructed and plan on putting down yard fabric to slow down grass and weed growth.



Is it better to have the playground sitting on the dirt or something like 5/8" Minus Crushed Aggregate? I'm concerned about the wood rotting where it is touching the dirt. I will also be adding 6" to 12" of mulch or something else soft in case of a fall.

Playground Footing - Gravel or Dirt beneath the structure - Sunray Premium Playground from CostCo?
How about just putting the agregate where the playset touches the ground? You could dig out a hole about a foot in diameter and a few inches deep, and then fill it with the agregate. This would provide the drainage to keep the wood from rotting, it would be less expensive and easier than putting agregate down in the whole area, and you don't have to worry about the kids falling on a bare agregate surface (if the mulch or whatever gets pushed out of the way in spots).
Reply:What I do for decks is to dig about 4 foot deep hole. Pour about 2 foot of dry quickcrete (I add to get my posts as close to the desired height as possible.) This will also help reduce settling! Then I set the posts and fill the hole with mixed quickcrete. This way the timber never comes in contact with dirt. (I still use treated posts!)