Hi I’m new here, I came across your thread from a google search.
I’ve just put up a cabin / garage, similar size to yours and I made the base ever so slightly bigger than the cabin
.. I’m seeing damp around the edges, I’ve been told to put a skirt around the cabin, but I’ve not seen any examples of this anywhere. I’m worried that water will get between the DPM and the wood. Have you gotten around to sorting yours yet?
p.s. I know what you mean about running cables in 20mm conduit. A real pain and I was left wishing I went for 25mm instead.