Ceiling lights

[solo3uk]

Could somebody advise me please. Yesterday I went to see a friend of a friend who asked for my advice about his plumbing as I also know about that. His problem is that a Corgi registered plumber has recently installed in his top flat of a converted house a pump supplying two power showers, one for the guest room and another for the bathroom. He has an indirect cold water suply with a 250 litre tank in the loft and the pump empties it when both showers are on for about 4 minutes when in fact it should be able to supply enough water for 8 minutes.

The plumber told him he would have to install an additional tank but as the joists in the loft were too weak he didn`t dare without a structural survey by a qualified person. We went to the loft and I noticed the tank was fed from a 15mm pipe only. I suggested he changed the supply pipe to 22mm which in fact will supply water to over twice the rate of a 15mm pipe. Any suggestion about this will be welcomed.

I know you are asking yourselves what on earth has plumbing to do with the electrical forum?, well when he moved in that flat about 18 months ago an electrician had fitted about 25 ceiling halogen lights all over the house. The fibreglass insulation was pulled back on each light and the lights were not capped by any smoke or fire protection, they were just skeleton lights, therefore the loft was lit like a mini Battle of Britain with miniature searh lights all over the loft. The cables joining each other were lying on top of the joists so if somebody boarded the loft up would pinch the cables. I know the cables would contravene the regs but my question is this: because the lights were fitted on a ceiling above which is the loft and not another dwelling, do the regs demand smoke and fire protection in this case too?. I think so as the regs don`t elaborate on this.

My friend said that soon after the electrician had finished his job somebody else came to inspect his work. He paid several thousand pounds for the electrical work and I wonder if I could even give him a certificate after all that money spent.

Any comments will be most welcomed.

[professorgbr]

Hi
The ceiling is a fire break and the lights should be fire rated as cutting holes in the ceiling is breaching its fire rating also lofts get filled with junk and the christmas tree etc and downlighters can be a source of ignition
As for the water tanks compare the water delivery lpm at the ball valve with both shower pumps delivery volume you would increase the volume with a 22mm pipe but the supply needs to be up to the job too

[solo3uk]

Thank you Professor, I wasn`t sure that because there wasn`t living accommodation above the ceiling the lights could be dispensed with the fire protection.

After posting my request it occurred to me that by increasing the feed pipe to 22mm the supply might not be up to the job, as there is only 15mm at the main stop cock.

[sparkysi]

Proff is right re the electrics, they should be fire rated which does not always mean they are fully enclosed, IP rated units for the bathroom for example are not fully enclosed fittings even though they are fire rated.

Re the plumbing, You will need to check the incoming supply pipe size, if its a blue poly then you can tap off in 22mm and gain some extra flow, although it will not be double, more like 40~50% more IIRC. You will need to uprate the stop tap to suit as well. If the supply is an old lead feed then not only ought it be replaced but you will also struggle to gain anything from upping the pipe on the consumer side, this is because the inside diameter of lead pipe is much smaller than that of poly.

I would also suggest that the least of your worries is the loft tank feed. Dont forget that the tank also feeds the water into the hot water cylinder, this can only heat water at a given rate and only has a limited capacity so the first weak point will most likely be the storage cylinder.

If it were my job, I would be encouraging your friend to seriously consider going for a good quality combi boiler which can supply the demands he has. You can then get rid of the pumps and lose the worries over the supply pipe.

Cheers