Concrete shed base

[leeb1450]

My back yard has a concrete base about 4" thick. I would like to build a shed/workshop 12'x10' with a concrete base of about 6". can i lay new concrete over the top or do i have to dig up the old stuff and start again.
Thanks :?

[stoneyboy]

leeb1450,
Lay the 6" ontop of the existing slab.
end

[leeb1450]

Thanks I will give it a try