Shower wiring?!

[ABCwarrior]

Planning to install a 9kw instant shower in the upstairs bathroom, keeping the bath etc.
There is no capacity on the CU to run a cable so I need another small CU to allow this(and to allow capacity for running power to a workshop at a later date)
My main questions relate to routing the wiring. The CU is in the utility room centrally in the house, ground floor. The bath is upstairs directly above the ceiling across the other side of the utility room from the CU. I plan to run the cable in surface mounted conduit up from the new CU then around the corners to below the bath and up through the floor. Ideally I want to cut a decent chase down the narrow end of the bath wall and run the cable up inside the cavity to the height it needs to be(whole lot will be marine ply-ed and then tiled after so can afford to cut into the plasterboard)
Should I run the cable in the cavity inside a metal pipe of some sort? The plumbing will be routed up into the wall too I don't want pipes and conduit on the tiled surface.
Can anyone advise of any LA, legal issues and whether this needs signed off to keep insurers happy? This is a concern now it's a bought house, my last housing association place I fully installed all the wiring and plumbing(including retrofitting the prehistoric CU to take a modern RCD, hacksaw job....!!) and had no worries but the shower wall was through from the immersion cupboard which had the CU in it so everything was visible.
The wiring will be 10mm2 even though it's a short run...

 

[sparkwright]

No mention of a double pole switch; pull cord in bathroom or wall mounted switch usually just outside the bathroom.

Is your current cu quite modern, or would it benefit from replacement?

 

[sparkwright]

No need to run the cable in a metal conduit in the plasterboard wall, assuming it is in a cable safe zone, and will not get screwed through.

Avoid the cable touching any pipework.

I take it you are using twin and earth cable.

 

[ABCwarrior]

Was planning to put a wall mounted switch near the CU as the bathroom has a sloped ceiling(no horizontal surfaces....), or could wall mount it externally in the hall, easy enough to put in a dwang(noggin) to take the box from inside the bathroom before boarding it up etc)
The house is new last year, unfortunately the last available RCD slot was taken when they put in another 3kw immersion element as it was taking hours to heat a 210 litre thermal store with just the one at the top of the tank (and the multifuel stove was hideously under capacity for heating water...architect is a berk...)
I'm a conservation stonemason BTW with HNC Building, not exactly a DIY novice. I could safely do this but it's just compliance with any regs(Scotland) and compromising insurance that concerns me and I don't know any sparkys to go and bother
Does all that Part P stuff affect replacing ceiling light roses etc? Our wall lights are permanent but the other half wants uplighters, easy to do but is that under the suffocating blanket of bureaucracy foisted upon us by the EU now?

 

[ABCwarrior]

Aye twin and earth, switch will be a 40/45A(? well the one I took out the flat when I reinstated it to how I got it...!)
As far as the pipework goes I'm probably going to use HEp2 or some form of push fit connectors rather than compression so earthing them isn't an issue(? or is it??!!!)

 

[OwainDIYer]

Part P does not apply in Scotland. Under Scottish Building Standards, installing an electric shower or an extractor fan is NOT notifiable.

Any work associated with the installation of a single sanitary facility (excluding a water closet, waterless closet or urinal), including any relevant branch soil or waste pipe, is NOT notifiable.

Work associated with the formation of a new bathroom, shower room, kitchen or utility room IS NOTIFIABLE in a Flat, or a House of 3+ storeys. It is NOT notifiable in a house of 1 or 2 storeys.

Building Standards FAQs

 

[ABCwarrior]

Cheers for the replies. A hefty does of forethought and common sense should do then!?
I'd rather do the job myself to my own high standards than pay someone to come in and do the job then worry if they've done it right!!! Our new house has got some shockingly bad workmanship, notably the plumbing and plastering, and it seems as if each trade is oblivious to any sort of "holistic" approach, damaging/compromising important parts of the build as they carry out their own work.
As I say- cutting a detailed piece of stoneworkl I get no second chances, it has to be right first time and for me attempting others trades is no different!

 

[ban-all-sheds]

• For a circuit to supply a given load (doesn't matter what), how would you go about deciding what cable and protective device to use?
  
  
• How do you calculate maximum demand and how can diversity be used?
  
  
• What are the 3 different types of domestic single-phase supplies provided in this country, how would you recognise them, and what differences do each make to the requirements for the rest of the installation, particularly any outdoor supplies?
  
  
• Can you correctly identify all components and connections of a circuit by method of testing or otherwise? In doing so can you identify or recognise anything wrong or dangerous with the circuit?
  
  
• Do you understand how the way in which you install cables affects how much current they can carry?
  
  
• What are the rules concerning cables concealed in walls, partitions and under floors?
  
  
• What are the rules for cables run outdoors, buried in the ground or overhead?
  
  
• Where cables need to be joined, how should this be done / not be done and in what circumstances are different methods acceptable?
  
  
• Can you identify extraneous conductive parts, and do you know the requirements for main and supplementary bonding of them?
  
  
• Which circuits should be RCD protected?
  
  
• How do you propose to isolate your supply so that you can connect up your new CU?
  
  
• Can you explain what tests you would carry out on the installation - what sequence you'd do them in and at what point you would energise the installation, and for each test do you know what is being measured, why it is important, how you would carry out the test, and with what equipment, and what sort of results you would expect to get if everything was OK?

 

[LoveRocket]

• For a circuit to supply a given load (doesn't matter what), how would you go about deciding what cable and protective device to use?
  
  
• How do you calculate maximum demand and how can diversity be used?
  
  
• What are the 3 different types of domestic single-phase supplies provided in this country, how would you recognise them, and what differences do each make to the requirements for the rest of the installation, particularly any outdoor supplies?
  
  
• Can you correctly identify all components and connections of a circuit by method of testing or otherwise? In doing so can you identify or recognise anything wrong or dangerous with the circuit?
  
  
• Do you understand how the way in which you install cables affects how much current they can carry?
  
  
• What are the rules concerning cables concealed in walls, partitions and under floors?
  
  
• What are the rules for cables run outdoors, buried in the ground or overhead?
  
  
• Where cables need to be joined, how should this be done / not be done and in what circumstances are different methods acceptable?
  
  
• Can you identify extraneous conductive parts, and do you know the requirements for main and supplementary bonding of them?
  
  
• Which circuits should be RCD protected?
  
  
• How do you propose to isolate your supply so that you can connect up your new CU?
  
  
• Can you explain what tests you would carry out on the installation - what sequence you'd do them in and at what point you would energise the installation, and for each test do you know what is being measured, why it is important, how you would carry out the test, and with what equipment, and what sort of results you would expect to get if everything was OK?

Yeah! Yeah yeah YEAH! Oh yeah! Oooooh yeah!

 

[ban-all-sheds]

And the value of that contribution was what, exactly?

Would you care to explain why someone installing a new CU and new final circuits doesn't have to worry about any of those things?

 

[holmslaw]

..

 

[LoveRocket]

• For a circuit to supply a given load (doesn't matter what), how would you go about deciding what cable and protective device to use?
  
  
• How do you calculate maximum demand and how can diversity be used?
  
  
• What are the 3 different types of domestic single-phase supplies provided in this country, how would you recognise them, and what differences do each make to the requirements for the rest of the installation, particularly any outdoor supplies?
  
  
• Can you correctly identify all components and connections of a circuit by method of testing or otherwise? In doing so can you identify or recognise anything wrong or dangerous with the circuit?
  
  
• Do you understand how the way in which you install cables affects how much current they can carry?
  
  
• What are the rules concerning cables concealed in walls, partitions and under floors?
  
  
• What are the rules for cables run outdoors, buried in the ground or overhead?
  
  
• Where cables need to be joined, how should this be done / not be done and in what circumstances are different methods acceptable?
  
  
• Can you identify extraneous conductive parts, and do you know the requirements for main and supplementary bonding of them?
  
  
• Which circuits should be RCD protected?
  
  
• How do you propose to isolate your supply so that you can connect up your new CU?
  
  
• Can you explain what tests you would carry out on the installation - what sequence you'd do them in and at what point you would energise the installation, and for each test do you know what is being measured, why it is important, how you would carry out the test, and with what equipment, and what sort of results you would expect to get if everything was OK?

Yeah! Yeah yeah YEAH! Oh yeah! Oooooh yeah!

Do you ejaculate everytime you paste (sorry) that in to a reply?

 

[ban-all-sheds]

LR - will you please answer the following questions:

1) When can the readers of this forum expect you to stop behaving in this childish way?

2) Why someone installing a new CU and new final circuits doesn't have to worry about any of those things?

3) Why you think that this forum benefits from your presence when you seek to devalue important safety advice because you won't even stop at risking peoples lives in order to have yet another of your tedious and pathetic personal digs at me?