Excellent information thank you. If I understand correctly you used the spacing boards between the joists to hide the bolt fixings. Does this mean you recessed the thread and bolts into the wall ledger plate itself?
I wont need to do this for the rear wall as a secondary wall will hide the wall plate, so I will just use joist hangers. For the front wall I think I will do as you have done. Did you fix the joists in any way or were they held in place by the spacer plates. How long were the 8mm screws you used? How far into the joist are they screwed? Seems mad to me that they take all that weight?
Also it seems like 1 metre spacing for the wall bolts is quite wide but it’s a lot less drilling, especially into granite? I have a twelve metre wall to do with three seperate wall plates. (front and rear) I was thinking I should buy stainless steel threaded rod not galvanised? Where did you source the resin? In James’ original post he used Screwfix own brand - Non Nonsense Resin Anchor. I can’t find this on the Screwfix France site? They don’t seem to have much compared to the UK site?