Q & A of the Day – What is the best way to repair a nail damaged cable in a wall?

 

Question: I came across this query whilst surfing a popular Internet deal website.

 

Somebody reported that he had wanted to hang a picture and, in doing so, had put a nail right through an electric cable buried in the wall - and was asking for advice.

 

The advice given on this website did vary, but generally, the idea (including from alleged tradesmen) was to chase out the hole where the nail had gone in, strip back the cables, crimp them, and then re-plaster the wall.

 

Now as far as I understand the Regulations, all joints have to be accessible and enclosed, so that no terminations can be accidentaly touched.

 

What – in your opinion - is the correct method to repair the damaged cable?

 

Answer: Regulation 526.3 requires connections to be accessible for inspection, testing and maintenance, with a number of exceptions, which includes a connection made by an appropriate compression tool - so the joint made with crimps does not in fact need to be accessible. 

 

It does, however, have to comply with the other requirements in BS 7671:2008 (2011) for electrical connections in Section 526, which includes that every termination and joint in a live conductor is made within either a suitable accessory complying with the appropriate product standard, an equipment enclosure complying with a product standard, or an enclosure partially formed or completed with building material that is non-combustible when tested to BS 476-4.

 

The crimped connections should, therefore, be suitably enclosed.

 

Note: Where cables are buried in walls less than 50mm from the surface, the requirements of Regulations 522.6.101 and 522.6.102 should also be considered.