I am going to build a workshop this spring and move out of the basement. I am planning a 30 x 40 building with 9 foot ceilings. My big concern is the floor. I would like a wood floor and not concrete. I was thinking at first of having an insulated slab pured and then placing placing wood 2x anchored to the concrete and then plywood and oak on top. I have 1000's bf of airdried oak that I will use for the final floor. Then the though accoured to me to just pour colums and build a joist floor system out of treated lumber. Filling between the joists with gravel, placing a vapor barrier down and then plywood with the oak finish on tope. Any thoughts. I want to make sure the critters have a hard time getting in since we live out in the sticks and that is the reason for the gravel between the joists. The building will be heated. Any thoughts or questions would be approciated.