electric shock from floor to earthed metal sink

[kipper]

hi all electric shock from old brick floor layed on soil, to earthed out kitchen sink 0.68ohms earth loop reading.
in a 400 year old farm house connected on p.m.e.
its been happening for a month (since rain)
any ideas why and how to over come?
ta kipper,

 

[Wiresandthings]

Could be a DNO issue with neutral/earth now being live and live being neutral/earth, especially if they have recently done some work on the lines?! Just an idea as its pme

 

[Richard Burns]

If the floor has become live then some connection to that floor is the fault, this is likely to be metallic pipework connected to the live supply somewhere..
If the protective device has not tripped on that circuit then it would appear that earthing or bonding is not in place.