damp problems

[comptonspark]

looked at a job today in a small outbuilding where the RCD has been tripping after heavy rain. On IR testing I've isolated the fault to the ring main and specifically the part of the ring at one end of the building where there are some obvious signs of damp in the solid stone/brick wall.

So I removed the sockets and sure enough there is damp in the metal back boxes and some drips of water off the ends of the cables. So I IR'ed the buried cables (direct into the wall) on their own and was still getting very low readings (between 0.1Mohms and 23Mohms depending on the part of the ring that I tested).I would have thought that by removing the sockets and cleaning up the ends of the cables a bit I would have got slightly higher readings? - I'm assuming that the T&E cable should be impervious to water or am I wrong on ths point?.

Was going to recommend a rewire of the affected part of the ring using surface wiring and sockets with plastic boxes. Should this solve the damp problem?. any other ideas welcome.

thanks - Michael

 

[telectrix]

IP65 surface sockets wired in 20mm plastic conduit is an option

 

[Deleted member 9648]

Selection and erection guidance note states that PVC cable can absorb water over a period of time and is not impervious....it was talking about total immersion though........I'd go with telectrix's suggestion,the environment does not sound suitable for a flush install.