Bathroom lights - what's allowed/required?

[usenet]

One of the first jobs to tackle in refitting the bathroom at our flat will be the lighting. We're going to put up a pine T&G ceiling which will be supported on battens screwed to the 'real' ceiling, thus there will be space for the lights, wiring, etc. in the space behind the T&G. (The 'real' ceiling is solid concrete as far as I can detect, there's no access beyond it).

What sort of lights must I, can I or should I have? Are they required by the regulations to be of a specific IP rating or anything, or designated as bathroom lights, or what? Is there any more specific requirement for any lights which are actually above the bath? Six downlighters is probably what we'll go for, the ones at my mother-in-laws house are very satisfactory in the bathroom.

The ceiling is quite high (thus the false T&G ceiling presents no problem), it's distinctly more than the normal modern house ceiling height.

As a minor additional question what sorts of lights and switches can one have above a washbasin, are only pull switches allowed for such lights? (It'll be pretty close to the bath, it's not a big bathroom).

[BigWallop]

Firstly Chris, any switch gear should either be a normal plate switch outside the bathroom or a pull cord switch if it is to be used within the room itself. Normal plate switches can arc over to damp hands, which is not a very nice feeling.

The lights should marked as being able to use in a bathroom and are normally sealed dichroic low voltage systems. I think B&Q are doing them very cheap at the moment, or so I am told, with a gang of three arrangement.

You say that six lights should be enough, so taking two of these sized systems from the existing supply should not cause any problems.

The space above the lights will need to allow good ventilation though, as these little lights can give off a good bit of heat if they're on for long periods, and I normally tell folks to leave a good 75mm above them to a solid ceiling for this very reason.

The transformers used on these units are slim enough to slip into the space left for the light fittings, so that should also not cause you any problems. But the only other advice I give, is for you to leave a small gap all around them to let them dissipate their heat properly too. So lifting them on to small blocks of wood at each end of the unit should be enough. Anything to let air get all around them as much as possible.

[Christian McArdle]

The exact height of the ceiling is very important in determining the answer. Can you measure it? It will reflect on which zone the ceiling is, in various locations. The zone determines the IP rating required.

If we can assume that the ceiling is between 2.25m and 3m from the floor, then it will be Zone 2 above the bath/shower, Zone 3 within 60cm of the shower/bath and unzoned more than 60cm from the shower/bath. This means you need IPX4 (where X is any number) fittings right above the shower/bath. However, outside this area, any fitting can be used, provided you don't intend to use a hose to clean your bathroom. If you do intend to use a hose, you must use IPX5. IPX4 means splash resistant. IPX5 means resistant to water jets.

If it is more than 60cm from the bath and shower, there is no blanket requirement to use pull cord switches or use special light fittings. However, there is a general requirement to use switches and luminaires suitable for their location. Having a live switch right above a basin might not be considered a good idea. I've heard 30cm being considered a rule of thumb to determine how far from a sink an accessory should be installed.

Christian.

[Roger Wareham]

Take a look at:

[usenet]

That's already the situation of course.

A 35 watt light will always give off 35 watts of heat won't it? Presumably if one gets the 'forward reflecting IR' variety more of the heat gets radiated down into the bathroom rather than left in the void. Does anyone know if this really makes a lot of difference>

[Tim Mitchell]

In article , BigWallop writes

We have some of the B&Q ones, 3 lamps on one transformer. If one lamp of the 3 blows, you must change it immediately, otherwise the other 2 lamps will also blow within a few minutes. Presumably there is no regulation on the transformer.

They give a nice light quality in the bathroom, if you like that sort of thing, I know some people who hate downlighters.

[usenet]

Ah, thanks, that was the detail I wanted, I thought there was something related to height involved in the type of fitting allowed. I'm sure the (false) ceiling will be more than 2.25 metres above the floor, it *might* be more than 3 metres, I'll check. Anyway if I go for IPx4 fittings they'll be OK regardless (not aiming to use a hose in the bathroom!). Thanks.

It *might* be within 60cm of the bath, the washbasin is close to the non tap end of the bath. I'll check on that as well. Does that 60cm mean the switch needs to be more than 60cm from any part of the bath or what exactly?

[usenet]

Very useful, thanks.

[Christian McArdle]

Also, they must also be suitable for location. If the manufacturer of the fitting states "not for use in bathrooms", then it mustn't be fitted, even outside the zones, as the manufacturer has asserted that they are not suitable.

Measured from any part of the bath or shower, horizontally. Taps are irrelevent. It is about keeping stuff away from the reach of someone using the bath or shower. However, I'm still not entirely sure I'm right. There seems to be disagreement about whether standard switches can be installed in Zone 3. I haven't got the regs in front of me to check the definitive answer.

Christian.

[Andrew Gabriel]

Yes it does, but you'll be lucky if you can still find fully aluminised MR16's -- it's become almost impossible to buy anything other than dichroics nowadays.

[usenet]

OK, thanks.

The PDF document that someone else pointed to from this thread is quite useful. The washbasin will certainly be within 60 cms of the bath horizontally but it could well be arranged that the switch for the light is further away than that. We're not quite sure what sort of light to have above the washbasin yet so details of that bit are still somewhat vague.

[Witchy]

Interesting! When I put the lighting in our bathroom the only questions I asked here were about number of lights and what might overload the circuit - I figured the ceiling was high enough to make it unzoned.

I ended up with a 50W shower downlighter over the shower, 2 bathroom-suitable pearl glass globes on either side of the shower and

2 bog-standard 20W low voltage downlighters over the bath and sink, reasoning that the ceiling is at least 6 feet away from both and as such you'd have to be going some to get water up that high. The telephone type shower attachment on the bath taps is at the opposite end of the bath to where the downlighter is, if you see what I mean. I don't think it's powerful enough to get that high up the wall!

My only concern is that because we've built an open shower steam can sometimes get that high and I might have to fit some sort of fan to the outside wall. Something to be worried about?

cheers

witchy/binarydinosaurs

[BigWallop]

Have you ever tried splashing up that high when you're drunk ? I don't mean with shower. :-))

[Witchy]

Hehehe! Given where the bog is in relation to the downlighter there would have to be some superhuman feats involved here.....

cheers

witchy/binarydinosaurs

[N. Thornton]

If you do, you're throwing heated air out, like pointing a small fan heater outside. A crossflow exchanger would mean you retain the majority of the heat while still changing the wet air for dry.

Regards, NT

[Witchy]

I didn't know such a beast existed....ta! I'll have a google around.

cheers

witchy/binarydinosaurs

[N. Thornton]

Hi. Finally remembered the name of them, Heat Recovery Ventilation, HRV.

Regards, NT