Will My DPM Work

[Spooked]

Hi all.
I have a timber framed shed/workshop sitting on a concrete slab.
I have serious damp rot and woodworm in the perimeter base timber I put around the edge of the concrete slab for the uprights to sit on.
I can replace this timber in sections by jacking the shed up slightly.
As you can see from the drawing, to the left of the shed where the ground is higher is a second concrete block, a path.
If I slip a DPM (blue line in the drawing) under the uprights and make sure it's above the floor level of the concrete path, then put my base plate timber on top of the DPM will this stop the problem recurring?
Cheers

 

[JohnD]

in your diagram, rain can run under the shed and lie on top of the DPM.

You would do better to use an impervious material, such as a single course of bricks, or paving slabs, with DPC on top, and stand your shed on that. air can circulate in the space and help keep it dry.

it is an advantage to have the concrete slab for a shed slightly smaller than the shed, so that rain cannot fall on it.

 

[Spooked]

Thanks for the reply JohnD.
Sorry, my first pic was sh*^e!!
I have tried again.
The right hand side of the shed, which is level with the ground, doesn't appear to have a problem.
I need to put a concrete fillet from the concrete path to the outer cladding to stop water ingressing there.
That will likely cure a good part of the problem.
I was hoping that my proposed DPM would act as a second barrier.
What ya think?