It looks like I may be able to build my new workshop come spring, *just* within the 15 sq.m limit (so it doesn't have to be 1m from next door's garage-on-the-boundary, Grrr...), and wonder if anyone has any suggestions for putting a DPM / DPC in - the slab will (I think) be 6" concrete with 2 layers of steel fabric, sat on 2" of expanded poly (warm feet in the workshop - ooh, lovely!) - is there any advantage to taking the DPM below the insulation, assuming I don't poke holes in it? At present I'm hoping the walls will be concrete block with more insulation/vapour barrier/ply-or-platerboard on the inside, should the DPM come up from the slab to surround the first course of blocks, or would it be better/easier to put the DPM internal to the walls and slab, and screed over? I'd rather avoid any brittleness from a thin screed as there'll be 2 tons of lathe (and, funds permitting, a ton and a half of milling machine) sat in the 'shop once it's up, hence the need for a Substantial Slab!
Thanks in advance for any suggestions, Dave H.