[Closed] New/rebuild shed time.....

Firstly I already have a 9'x7' concrete slab down (with a polythene damp course underneath it), I was gonna replace one wall and one end and raise the roof by about a foot on the current shed, but have noticed today that the floor is quite damp, so do I.....dismantle whole shed,put new bearers down on DPC on the pad and rebuild old shed, or put a course of concrete blocks down, render them and rebuild the shed on those and use the concrete pad as the shed floor, I'm quite handy, and have mates in the trade, so any things possible, though it needs to be completed over a weekend ideally, the shed is on a slight gradient and I don't want damp in through the floor again