Electrical condition reports

I think as a rule the general public are probably unaware of the recommendations that an Electrical Installation is Tested and Inspected every 10 years or every change of occupancy or ownership. Why does the I.E.T recommend this? Various reasons, electricity is generally supplied at 50Hz which means that it constantly vibrates, over time this can cause the terminal screws in sockets, switches, lights, and junction boxes to become loose which causes arcing and a build up of heat. In some cases this can lead to fires although usually the circuit protective device operates before any major damage is done. Another reason for Test and Inspection is to check that any additions or alterations to the installation have been carried out in accordance with wiring regulations and in a safe manner. The reason I mention this today is due to two call outs I have attended in the last month, the first was a privately owned home that had lost all power to their sockets, the family had moved into their home about three years ago and during the process of purchasing the house had a surveyors report as most do. Because of this they assumed that everything was in good order unfortunately this couldn't have been further from the truth, the previous owner had wired additional points and all the electrical lights and sockets in an extension to the house, some sockets had been wired in lighting cable and the socket ring circuit capable of carrying 32amps had been split reducing its capacity by half although still supplied by a 32amp circuit breaker. The sockets in the kitchen extension had been wired via a multitude of junction boxes in the loft space and in one of these the terminals had become loose leading to arcing which in turn caused the wires and indeed the junction box to melt and short circuit hence the lack of power. The second property was a rental, I was called out as the new tenants had just moved in and found that the kitchen light was the only one working. On investigation I found loose bare live wires not connected in one of the ceiling roses and in another the circuit protective conductor in the neutral connection. These are just a couple of examples that I have come across recently but in both cases for the sake of £100 for an Electrical Test and Inspection much aggravation and inconvenience could have been avoided and peoples lives not risked.