Bathroom wiring - what can I DIY?

Paul123 · Jun 13, 2020

Got a few changes I wanted to make in the bathroom, just searching through the threads there are all sorts of regs and zones and acronyms as a DIY-er I'm not familiar with. Following are the jobs I want to do, give or take I've got all the parts but now wondering if I should be doing these myself. Would appreciate yes/no's on if its possible and if I can take this on or I should seek a qualified electrician?

1. Replacing the existing lightfittings with new ones.
2. Adding an additional single light on a seperate switch (so going to the bathroom at night I can flick on a single light with a low wattage bulb so I don't blind myself with the four main lights, this idea came from a hotel I stayed in).
3. The extractor fan is currently wired to the light circuit, I want to move this to a seperate circuit/switch. I have got a fan isolator switch to go on the landing which it currently doesn't have to isolate the constant feed as it does have a run on timer.
4. The lights are currently switched from a pull switch in the bathroom, I want to take this out and add switches on the landing (for the 3 above mentioned circuits).
5. Adding a shaver/toothbrush charger socket in a cupboard in the bathroom (and would this go to the upstairs socket ring main or be wired to the lighting circuit, can't see any indication on the unit I've purchased to what ampage it requires feeding with).
6. I have an instant hot water shower, currently this is switched from a 45amp pull switch in the bathroom. In 4 years this has been replaced 4 times, as the switch just breaks, 3 times in the off position resulting in not being able to shower

. I'd like to take this out, and replace it with a 45amp 'cooker switch' on the landing, is that allowed? It's being fed direct from the consumer unit, has its own RCD (if thats the right terminology?) and 10mm2 twin and earth feeding it.

westward10 · Jun 13, 2020

It is difficult to say without knowing where your electrical skills fall. No 1 maybe but they would require compliant connection, assuming these are downlights as you mention four lights in No 2. The other items require more knowledge and your comments in No 5 suggests these works are outside the scope of you knowledge/ability. There are other factors to consider such as additional rcd protection and the suitability of existing earthing and bonding arrangements.

marconi · Jun 13, 2020

It is over used these days but it is succinct - you don't know what you don't (need to) know to do this work so that it is compliant and safe and will satisfy your insurers. Why take the risk? Work done well with certificates adds value if you ever want to sell.

Paul123 · Jun 19, 2020

Thanks for the input westward10, understand what you say that you don't know what my knowledge/experience is. Assume your referal to my comments in no 5 is the "If thats the right terminology" I know what things are/do just not necesarily what they are correctly named, and this being my first post I didn't want to come in all sure of myself in case I got it wrong.

In honesty I wasn't sure what response I'd get on here with electricians at varying levels responding. I understand the correct answer is all home electrics should be done by an experienced/qualified electrician but in the process of an entire house renovation so if I can save a hundred quid or so here that can go towards the next job.

No1 (and 2) yes are downlights, the 4 in no1 would be replacement of 4 existing downlights, the only major change would be I'd need to replace the initial feed with a longer cable to come down the wall to a switch rather than being in to the current pull switch in the ceiling so I'd trace this back to where the current feed joins the main circuit and run a new longer cable (rather than jointing/extending the existing cable).

For me electrical circuits are logical and I am a bit vulcan in that sense. Undergoing work like this I will look and draw the current circuit, plan/draw the changes then complete once I'm happy. I've done a couple of lighting circuits (one in the loft and one in an outhouse).
I guess I'm trusting in the current setup meeting regulation to copy/expand it, but I don't know what regulation may have changed since that was wired in so thats probably where I fall down.

Maybe I've gone about this the wrong way, and I should put up the seperate jobs and what I plan to do for input as I'm working on them. 1,2 and 3 I'm happy with to be honest. 4 there's a few questions, 5 at 45 amps this is one I wasnt confident with and hoped to get some input on.

Marconi, you are correct, based on comments above about RCD protection, yes I wouldn't have even considered that. Assume going to a switch you touch with this ampage running through an RCD would need to be within a certain distance of cable from where the switch is to give closer/quicker reaction should a short occur which is where I hoped to get some guidance on here. And on that theory a bathroom socket would maybe need to be on a fused spur (if thats the right terminology ;-) ) like for an appliance in a kitchen.

marconi · Jun 20, 2020

Paul123: Thank you for your measured response above. For wiring design, a bathroom is classed as a 'special location' because of its make-up, water and use by folk in various states of nakedness and wetness - and formally notifiable under the UK's building regulations to the council building department. I hope this helps explain why professional electricians hesitate to provide advice to those that do DIY design and installation.

If it is any consolation I am a chartered electrical engineer but I am not a qualified in law electrician so I do not do such electrical work. If you are worried about the cost, shop around for three of four estimates.