RE: Slab under existing shed?

[Ken Landaiche <ken_landaiche@dlcc.com>]

I think your slab would be all right, especially since you won't be
driving on it. You will have a better job if you excavate a few inches
for some drain rock and sand. I found years ago with a similar situation
that a rototiller was a good tool to cut the dirt to a pretty uniform
depth, especially in clay soils. 

Ken Landaiche