Great care needs to be taken when choosing bathroom lighting as the regulations are strict concerning the type of light you use.
The bathroom mirror deserves some special attention and a diffused glass light either side will give a good general illumination where it is needed. The alternative is a halogen downlight from the ceiling or fluorescent strip light over the mirror. The latest generation of mirrors incorporate lights into mirrors themselves with sections of the reflective surface removed and lights fitted behind them. This is a very effective way of generating an even light and improving electrical safety.
For general illumination in the rest of the bathroom either use downlights for their refreshing halogen colour or a high output flush ceiling fitting to suit the décor.
Portable lights are not permitted in a bathroom so for mood lighting use ceiling mounted directional spotlights aimed away from the bath and at interesting features. Lights designed specifically fitted for showers are available and must be carefully fitted according to the instructions.
The following information is a guide to help you understand what fittings can be placed where. This is not an installation guide and reference should be made to the IEE Wirings Regulations (16th Edition) or a qualified electrician.
Firstly it is important to understand the rating by which bathroom and some outdoor lights are classified. IP rating stands for “Ingress Protection” and is always followed by two characters. The first character specifies the degree of protection against particles or solid objects. Staring with 0 for no protection it runs up to a maximum of 6, which is total protection against ingress of dust. Of more interest here is the second digit, which states the degree of protection from ingress of moisture. This ranges from 0 for no protection to eight for a light, which may be totally submerged in water up to a specified depth. The ratings, which interest us, are IPX4 (X is used in this case because there is no requirement in the regulations for a level of dust protection). Lights sold as IPX4 will have been tested for protection against water splashing from any direction.
Listed below are the zones into which a bathroom is split. In zones 1,2 &3, if there is a likelihood of a water jet being used for cleaning purposes a minimum of IPX5 is required.
Zone 0 is inside the bath or shower itself and any fittings used here must be low voltage (max 12v) and be rated IPX7, which is total protection when immersed in water.
Zone 1 is above the bath to a height of 2.25m. A min of IPX4 is required here.
Zone 2 is an area stretching to 0.6m outside the bath and above the bath if over 2.25m. An IP rating of at least IPX4 is required here.
Zone 3 is anywhere outside zones 0,1 and 2 (subject to specific limits) and where no water jet is likely to be used there is no IP rating required.
The IEE Regulations do not make specific reference to wash basins but in the opinion of The Lighting Association they should be treated as Zone 2 (i.e. IPX4).