damp proof on top of concrete

I had a 4cm deep 7x4 metre concrete base laid to erect a log cabin and they laid damp membrane between the type one and concrete.
The log cabin floor bearers go directly onto the concrete base to support the floor boards and I am wondering if there would be some benefit to covering the whole top of the base with a damp proof membrane before putting the floor bearers down?
I have membrane so it's no hassle/expense; just wondering if doing that could cause any issues.
Secondly, since the base was laid we've had weeks of torrential rain so I assume that the concrete will be damp inside; would it be beneficial to allow this to dry and roughly how long would I need to wait?
It's my first time with a project like this so any pearls of wisdom will be gratefully received.
Thanks for any info

You are better off with a strip of DPC under each bearer, and lap it up the side a little

Thanks for your reply.
I have considered that also; my thinking with regard to covering the whole concrete slab was to eliminate any moisture from the concrete from causing problems to the wooden flooring or dampness inside the building. I'm perhaps being a bit OTT and I should stop over thinking it!
Any reason not to do this do you know?

The problem with your idea is that moisture will sit on the polythene and potentially keep the timbers permanently damp, or at least damper for longer than they should be

That makes sense thanks, I'll stick with dpc under the floor bearers then.
This whole condensation/moisture thing is doing my head in, the more I read the more confused I get!

The condensation issue in a timber shed/cabin is virtually zero