The Medway Handyman wrote:
Customer has had a shed base laid (not by me, I turned the job down) which
has turned into a bit of a disaster. Its off level by about an 1" in both
directions and the surface looks like a roller coaster for mice.

They want a metal shed erected on top, but there is no way thats going to
work until the base is sorted.

Initial thoughts are to erect level formwork & top the base with a little
more concrete.

Is it going to bond OK to the exciting base, especially where it
'feathers'.? Would PVA help?

Having read this thread so far, I am wondering why no one has mentioned
using treated wooden sleepers to sit the shed on, two by four the width
and a bit of the shed should be enough. All sheds need ventilation under
them.

To these sleepers attach blocks of the same wood and plane them down to
accomodate the hight difference across the concrete. The fact that the
concrete slopes is an advantage to stop rot and rust forming.

Dave