Posted: 17/03/2015 at 16:40
Sheds aren't that heavy so the base doesn't need to be that deep. If the slabs in place were relaid to a decent standard you could use them as a base, probably cheaper than a concrete base. But if you decide on concrete you can do it yourself. You create a frame just larger than the area of the shed, fixed into the ground with wooden stakes, mix your concrete, 1 part hardcore 2 parts sharp sand and two cement. It should be 4 inches deep. You'll need a mixer, you can rent them by the day or week. However it's often easier to get someone in to do it for you. It's not a big job. Just be careful where you put it though, you can't change things once the slab is down, you can if you use slabs, and they are different to lay but easier to take up.