How deep should wires be chased in to walls?

Hi Cheesepie Your electrician definitely should have used some sort of containment such as capping/conduit. That fact that you can see the cable is evidence that the cables are inadequately mechanically protected. All cables should either be contained in steel conduit or protected by 30mA RCD. If these two cannot be met, then the cables should be installed at least 50mm (2") from the surface.

hi he should have used oval tube or capping to protect the cables as its less than 50mm in the wall, the best way to rectify this is to do it correctly by putting oval tube in or capping also must be rcd protected

All electrical cables should be set into the walls at a minimum depth of 50mm if they are not mechanically protected. If it isn't possible to chase the walls to that depth then the cables should be set deep enough so that metal capping can cover them and allow for plaster to cover that. Such cables must also be protected by a 30mA RCD. This is a requirement of BS7671:2008 and can be found on page 74 of the On Site Guide.

I would assume he's issued an installation certificate and reported it to building control, then your installation is covered with backed up insurance if he don't rectify the fault, it would be done free of charge by the body he's registered with.

hi cables definatelly shouldn't be visible after plaster. they should be at least 25 mm (1") under the finish surface. If not they should be in plastic trunking (under the plaster) to avoid cracking for example... Anybody who pass BS7671 17th edition of wiring regulation should know that regards

BS7671:2008 requires that cables that are not encased in steel conduit and not RCD protected are chased in and buried at a depth of at least 50mm. If cables are installed at depths of less than 50mm then they must be either RCD protected or enclosed in steel tubing. Sounds like a very poor job, he may possibly not even be a registered electrician. Were you issued with a 6 year guarantee, and both building regulation and electrical test certificates for the job? - If not Alarm bells should be ringing as you've probably been had over!

Cables buried in plaster should be protected from damage by either capping with metal or plastic capping or by placing in conduit and if less than 50mm deep protected by a 30ma RCD

Hi, As a rule as long as you have the circuit that the cables are in protected by and RCD then you only have to chase them in as far as convenient for your plasterer. However you can chase them in further and place "capping" over them to offer protection from mechanical devices. ie someone drilling a hole to put up a shelf or painting. So as long as your sparks has the circuit protected by an RCD then Regulation wise it conforms. HOWEVER. Any decent tradesman would know that if they are not chased in at least flush then the plaster integrity around them is drastically weakened. So i would have him chase them in further and place capping or galvanized conduit in the wall. Then re-plaster. Main point is... "what a poor job." Unfortunately it may just be down to standard of work rather than a regulation you can pull him with. But unless he's a cowboy (which is in question because this should in NO WAY happen) he should see and rectify it. There is a flip side. Did the plasterer not do a thick enough skim.. Are they chased in correctly and the plastering job is poor? Sorry to possibly darken the mood, but its a possibility, although if it was me, the cables would be about 10mm in, capped and always secure. Regards John