ELECTRICITY IN THE BATHROOM
Water and electricity do not mix, so there are strict regulations listed in the Wiring Regulations of the Institution of Electrical Engineers about the electrical appliances you can and cannot use in the bathroom or in a room containing a shower.
The reason for complying with the Regulations is to avoid the risk of electric shock should a fault occur, and the metal casing of a piece of electrical equipment becomes ‘live’. In the bath or shower the damp human body is usually in direct contact with earth via the waste pipe and water supply pipes to the taps.
The Wiring Regs state that a switch or any other electric control must be sited so that it cannot be reached by anyone using the bath or shower. Ceiling-mounted, pulicord switches are allowed, but the switch body must be positioned out of reach. In an average-sized bathroom the light switch and the switch for any other electric equipment must either be a ceiling- mounting pull-switch or installed immediately outside the bathroom door.
Electric heaters (and electric-heated towel rails) are allowed in the bathroom provided they are not placed within reach of anyone using the bath or shower, and are permanently fixed to the floor, wall or ceiling. Under this regulation heaters can be mounted above a bath, but must be well out of reach of anyone standing in the bath.
Combined heat and light units for wall or ceiling mounting are useful for a bathroom, but they must be the type that has been designed specially for bathroom use, capable of withstanding damp conditions. They are not suitable for use on a lighting circuit as this cannot supply the higher power consumption.
All electrical equipment installed in a bathroom must be wired through a fused connection unit which is itself out of reach. The Wiring Regs. exclude the use of socket outlets in bathrooms because these would allow what the Regulations call ‘the indiscriminate use of apparatus, particularly portable appliances’ such as hair driers and heaters. Any other room containing a shower cubicle can have socket outlets but these must be sited at least 25m from the cubicle.
A special socket is allowed for shavers. This must be of the type for use in bathrooms, either on its own or with a light. The type for the bathroom – made to BS 3052 has an isolating transformer with an earthed metal screen so that the output winding is isolated from the mains. It is unsuitable for use with other equipment. The transformer has two sets of windings and most of these sockets will switch to give either the standard mains voltage or 115 volts. The socket is also usually made to take both round and flat pin razor plugs.
Washing machines which are properly and permanently installed and tumble driers can be fitted in bathrooms but their controls must be out of reach of anyone using a bath or shower. In most bathrooms this prevents the installation of these machines unless the room is very large or the machines can be isolated behind permanent screening, such as louvred panels, so that effectively they are in a room of their own. As a washing machine has to have a supply of water and empty through a waste pipe which will usually be on the bath side of the room, conforming to the Regulations may make plumbing both expensive and inconvenient.
The Regulations on lighting say ‘parts of a lampholder likely to be touched by a person replacing a lamp shall be constructed of, or shrouded in, insulating material and, for bayonet-type lampholders, be fitted with a protective shield’. So for bathroom lights either a special sort of lampholder with an extended skirt (sometimes called a Home Office or HO skirt) is required or a totally enclosed ceiling fitting should be used this can be lights behind a suspended ceiling.
If you want wall or down lights in a bathroom, they also must be totally enclosed, with no exposed metal parts, and of a type resistant to damp.