I am looking at how best to run a supply cable to a shed, all options with 4mm swa.

1) 20m run direct from main fuse board along brick wall that is bowing out and will have to be replaced due to structural issues, also small chance drilling will trigger cracks in the wall that must be strained by the bow.

2) Clipped to a brand new fence with some roses growing up it, not good practice, do water based wood treatments cause problems for insulation.

3) Bury it in a trench, trench likely to be disturbed when extension is built in a couple of years time.

So I don't have any really good options, partly because the cable route is much simpler option 2 seems best to me, but depends if water based wood treatments cause cables to break down. Also don't want to be responsible for a 6ft high brick wall collapsing on someone.

Interested in opinions of others and if anyone has data on the impact of water based wood treatment.