The LONG way to add an extra light to the room?

[MintMate]

Hi Guys

when we moved in our new house, we wanted to add an extra light in the front room (its all open plan and one light is just not quite enough for my liking). we are also getting a porch built at the minute and would like a light in there too. So the plan was, put the room light not too far away from the door, then the porch light could be taken from that.

The builder can access the light that is already in the room as the flooring is up in the bedroom directly above that light fitting thats already there.

The problem is, the wire would need to go through the joists to the location where i want the new light. (The next problem here is the rooms which the wire would need to pass under are already finished..New floors etc etc which i DO NOT want to take up), I also don't want to chip away the ceiling because thats brand new too, (I know there should have been some forward thinking here but there wasn't).

Any ways i've had an idea which is... As the flooring is up in the bedroom directly above the current room light, and that bedroom is going to be plastered, can a wire be ran from the light, through the joists, to the corner of the room, then up the wall into the loft (remember it will be plastered over), then down the soil pipe boxing (not in the soil pipe its self but the boxing around it) where access can be made without causing too much damage to the downstairs ceiling etc. Then both the new room light and porch light could be taken from this.

What i don't want to do is
Have this done against any building regulation
Cause more damage / work to finished rooms

The other thing is, what if i sell the house in the future, a new home owner may be confused about what that wire is there for and because its running upstairs, and into the loft, may not know its on the downstairs circuit.

Any advice would be greatly appreciated.

 

[PrenticeBoyofDerry]

When running cables you need to keep to permitted safe zones, also regulation will stipulate where and how a joist can be holed.
Links.
//www.diynot.com/wiki/electrics:installation_techniques:route
//www.diynot.com/wiki/electrics:installation_techniques:walls

Any cables hidden or buried within walls less than 50mm and not mechanically protected will require 30mA RCD protection, these may already be available at the board.

The layout of your rooms and the directions of joists, may help find a more direct route. Are you also opposed to bring the cable down and around the walls rather than up in to loft area?
Also regulations regarding depths of chases within walls, no greater than:
1/6th depth of wall (leaf/skin) horizontally.
1/3rd depth of wall (leaf/skin) vertically.

 

[MintMate]

Id rather not go upto the loft if i am honest but i also dont want to chisel away plaster work on the wall for the cables as the rooms and ceiling are newly finished. So the loft seems the more convenient option.

Ive taken a look at them links and the wire would go up the wall right in the corner of two walls, which dont have any adjacent rooms (shown in dark green on the diagram) and plaster boarded over and plaster skimmed over that.

On them images, i notice there are metal plates above where the wires run through the joists, this is quite an old house and they are not in here, is that a requirement or would it only be a requirment if it was rewired.

Thanks

 

[PrenticeBoyofDerry]

The metal plates over cables in joists, are because the joist have been notched, so "safe plates" are required to protect cable from mechanical damage (screws and nails etc in floor boards).
The method of notching joists is best avoided and holing is more desired, but the requirements of holing must be complied to, so cable avoids mechanical damage and the structure of the joist are not weakened.
What you intend to do as far routing cable up and down is not non-compliant, but the level of resistance in the circuit will be increased and Zs measurements will need to comply.
An option to shorten the length of cable, maybe to bring the the feed from the upstairs lighting circuit or possibly take a fused spur from a socket outlet.
Sometime you just have to concede that some damage to walls and ceilings is going to occur, regardless of how new the plaster and paint works is!

 

[MintMate]

An option to shorten the length of cable, maybe to bring the the feed from the upstairs lighting circuit or possibly take a fused spur from a socket outlet

I didnt realise that would be allowed if i am honest (having a downstairs light on the upstairs circuit) Incase say a new owner wanted to work on the light and switched the downstairs circuit off thinking that would be dead only to get a shock :s

However if it is allowed, i could literally half the length of the cable by taking the switch from the landing light and running the cable just down the soil pipe boxing. It really would literally half it.

Also once this work has been done (By the sparkie), does anyone need to inspect the work

Thanks for your replies

 

[PrenticeBoyofDerry]

I didnt realise that would be allowed if i am honest (having a downstairs light on the upstairs circuit) Incase say a new owner wanted to work on the light and switched the downstairs circuit off thinking that would be dead only to get a shock :s

It's not ideal but an option.
And does not contravene requirements.
It would be advisable to make remarks on documents and certificates issued, that this the method used and circuit chart and circuit labels at consumer unit indicate this.
Any one then working on this circuit would then have the relevant information at hand, and any electrician worth there salts would use the recognised methods of identifying circuits and proving the circuit was dead.

 

[PrenticeBoyofDerry]

Also once this work has been done (By the sparkie), does anyone need to inspect the work

No the sparky will just need to fill in either a electrical installation certificate or a minor works certificate. And label up the board accordingly, with any required circuit details and notices.

Take notice of RCD requirements!

 

[dhutch]

I have to admit, while its an shame its been plastered already, I would make some neat holes in the living room ceiling, run it where it ort to be, and get a plaster in for an afternoon to make it good.


Daniel

 

[PrenticeBoyofDerry]

I have to admit, while its an shame its been plastered already, I would make some neat holes in the living room ceiling, run it where it ort to be, and get a plaster in for an afternoon to make it good.

With you on that, I know it's a kick in the arse that you have finished before you have really have finished. But it's a shrug of the shoulders and crack on and think on for next time!

 

[ban-all-sheds]

The other thing is, what if i sell the house in the future, a new home owner may be confused about what that wire is there for and because its running upstairs, and into the loft, may not know its on the downstairs circuit.

As long as the routes comply with the regulations, you can install any cables wherever you like.

Nothing to stop you labelling cables at intervals.

 

[ban-all-sheds]

I didnt realise that would be allowed if i am honest (having a downstairs light on the upstairs circuit) Incase say a new owner wanted to work on the light and switched the downstairs circuit off thinking that would be dead only to get a shock

If somebody gets a shock because of faulty guesswork and assumptions and failure to follow safe procedures that is entirely their fault.

 

[dhutch]

You can also write on 'up stairs lights and porch' say. And or scrawl on the inside of the rose 'fed from upstairs lights' if you want!


Daniel