shed base help - concrete slab

[eggtastico]

Hey,
I have aquired a shed (10x8) from a friend & want to install it.
The only space I have available is a raised concrete slab that is big enough
for a shed.
My problem is that it isnt very flat.
I have put the shed wooden base/floor down & its quite bouncy under foot.
Would I be better off trying to level off the uneven base (its uneven in all directions) or maybe just put some 18mm plywood down on the base to make it less bouncy & hope the weight of the shed keeps it in place.

I have thought about maybe putting a layer of 20mm chippings down & placing the shed on that.
Any other alternative ways/cheap ways?

 

[mikej2005]

Don't put plywood onto the concrete base under the shed - it'll rot and isn't going to help with or solve the problem. It'll probably just make things worse.

I'm not sure that stone chippings will work either, as they'll move about on a concrete surface. If you did go down this route, they'd need to be contained somehow to stop them spilling over the sides of the base.

Personally, I would mortar in some strategically placed bricks - one in each corner (where the shed will go) and then a number in-between, placed where the shed base batons are located. You could then vary the thickness of mortar to get them all level or, if the differences in height are greater than you can get away with by varying mortar thickness, find bricks/blocks/slabs of different heights or cut them down with an angle-grinder to suit.

This approach would also have the benefit of raising the shed floor up off the concrete base. My own shed (left by the previous owners) is testament to the fact that any shed base batons touching a concrete floor will eventually rot with the rain that will collect under there.