Many thanks John. I forgot one other question: I was planning to put electric cabling in the void and poke it through the insulation where needed, sealing round it with foam. I think, from further trawling of the archives, that this shouldn't be an issue in terms of cables overheating for such...
Having trawled through dozens of similar questions, I imagine regulars here could probably live without another confused post about shed insulation, so my apologies, but…I’m confused.
Shed is a log cabin, 44mm T+G, with a pent roof. Should this work: batten out with 25mm deep timber, then...