Because water is such a highly efficient conductor of electric current, water and electricity form a very dangerous combination. For this reason, in terms of electricity bathrooms are potentially the most dangerous areas in your home. Where there are so many exposed metal pipes and fittings, combined with wet conditions regulations must be stringently observed if fatal accidents are to be avoided.
- Sockets must not be fitted in a bathroom – except for special shaving sockets that conform to BS EN 60742
- The IEEE wiring regulations stipulate that light switches in bathrooms must be outside zones 0 to 3. The best way to comply with this requirement is to fit only ceiling-mounted pull-cord switches.
- Any bathroom heater must comply with the IEEE wiring regulations.
- If you have a shower in a bedroom, it must be not less than 3m from any socket outlet, which must be protected by a 30 milliamp RCD.
- Light fittings must be well out of reach and shielded – so fit a close-mounted ceiling light, properly enclosed, rather than a pendant fitting.
- Never use a portable heater or other electrical appliance, such as a hairdryer, in a bathroom – even if it is plugged into a socket outside the bathroom.
In any bathroom there are many non-electrical metallic components, such as metal baths and basins, supply pipes to bath and basin taps, metal waste pipes, radiators, central heating pipework and so on – all of which can cause an accident during the time it would take for an electrical fault to blow a fuse or operate a miniature circuit breaker (MCB). To ensure that no dangerous voltages are created between metal parts, the Wiring Regulations stipulate that all these metal components must be connected one to another by a conductor which is itself connected to a terminal on an earthing block in the consumer unit. This is known as a supplementary bonding and is required for all bathrooms – even when there is no electrical equipment installed in the room, and even though the water and gas pipes are bonded to the consumer’s earth terminal near the consumer unit.
When electrical equipment such as a heater or shower is fitted in a bathroom, that too must be supplementary bonded by connecting its metalwork – such as the casing – to the non-electrical metal pipework, even though the appliance is connected to the earthing conductor in the supply cable.