Concrete base poured on 1200 membrane.

So, should I paint the base with damp proof coating too?

Perhaps belt and braces given base is minimum 80mm above surrounding ground and will be surrounded by granite chips for drainage.

No it won’t do anything. How is your actual shed base to be constructed?

I was told that the ‘shed’ should overhang the concrete/etc base by a couple of inches to stop rain etc pooling on the base and going under shed etc, if it didn’t get bit(s) of wood, dampcourse top it and put that under shed base to isolate it from wet/damp from underneath