We had two sheds in the garden, the 12' x 8' and an 8' x 6' which was directly behind it with one side against the end of the 12' x 8' shed. The 8' x 6' was on the same slabbed base as the 12' x 8' and all we want to do is move the 12' x 8' shed about 6ft back, further down the garden. As it is on a level base which already had a shed on it I'd rather not take it to bits if at all possible.
Has anyone tried this before and, if so, what method did you use and did it work?

Two methods spring to mind.

Jack one end of shed up and slide a large sheet of ply under it. Make a hole in the ply for a rope to go through and tow it, or jack one end up and put round fence posts under it and roll it to its new home.

See if you can borrow a few scaffold poles, put them under neath and roll it

round fence posts or scaffold poles ftw - needs about 3 of you (two to push and one to move the poles from the back to the front) but it makes it remarkably easy. They weren't stupid in olden times just technologically disadvantaged

Ply sheet method may work, moved engines around on uneven ground, no problem. Never tried moving a shed though. A couple of greased wooden skids may also work.

The roller approach may work though it depends on the orientation of the floor joists, shed orientation, direction etc. I've moved a 6x4 shed previously with limited success, they are very flimsy and don't take to being pulled/lifted/dragged etc from one point. Either lots of manpower lifting, via beams inserted under the shed (preferably empty.. ) or dismantle to avoid damage.

I seriously doubted poles would work as well - until 3 of us moved a shed about 30ft down the garden and rotated it 90 degrees, no significant damage at all

I moved a 6x4 shed using a car jack and some skate boards borrowed from neighbours kids.

Never thought about skateboards Slater, might be worth a think. I am worried about the structural integrity of the thing though, it isn't the strongest by any means and it may well 'lozenge' if subjected to, well, any stress at all! I think I might just have to schedule a weekend to empty it, take it to bits and move it the old-fashioned way

Moved a 13 by 9 steel shed a considerable distance. Lifted it and slid a timber frame under it to keep its shape, screwed the shed to the timber, put ropes on the timber and me and 5 others lifted it and carried it to its new home. About 150 meters away and 15 meters lower. Just more stuff to keep my place as the odd guy in the street.

If yoiu suspect its weak brace with timber diagonally inside

This is not much help I know, but, why don't you turn it into a 6x8 that way you only need a saw

[Edited on 16/9/2014 by philw]

I slid ours on a couple of wet staging planks, only takes a couple of people pushing and then it's off! There actually not very heavy

1/2 dozen strapping lads should be able to pick it up and walk with it.

Well that went far better than expected, the moving bit anyway. Emptied it, lifted it off its timber bearers with a 6ft pole and a fulcrum and onto four 6ft scaff poles, myself my father-in-law and son all got at the requisite end ready to shove for Britiain and it rolled as easy as anything Setting it down on the bearers was the reverse of lifting off, the bugger was getting it to sit level as the slabs it was on were rather uneven. Managed it in the end though, now all I've got to do it finish digging the 600mm+ deep trench for the longer power cable.
Through clay soil.
Oh joy!

600mm deep?! What ever for? If it's in clay you won't ever dig that deep otherwise, so I'd only go that far if there's particular reason for doing so. Admittedly my power feed for the garage is almost 4 ft deep, but only so I could find the water main and T off it in the same trench.

I just don't want to ever have to have an electrical survey of my house and have someone tell me the cable's not deep enough. Anyway, it's in and buried now, all I've got left to do is re-lay the slabs over the top of it and terminate the cable

Trust me, no-one was ever going to even think about digging it up to check!