Confused with so many rules

[Anya32]

Hi

I have had three electricians quote to wire my new kitchen which is currently a shell. The thing I don't understand is that they
seem to differ in their approach to the electrical rules, for instance, two are happy to place oven and hob isolation switches in a cupboard and one will not. One has suggested that he has to fix metal back boxes without plastic plugs but instead use expensive fixings. One has said that he cant run cables in the 150mm deep stud wall, very confusing!

 

[Dartlec]

Hi

I have had three electricians quote to wire my new kitchen which is currently a shell. The thing I don't understand is that they
seem to differ in their approach to the electrical rules, for instance, two are happy to place oven and hob isolation switches in a cupboard and one will not. One has suggested that he has to fix metal back boxes without plastic plugs but instead use expensive fixings. One has said that he cant run cables in the 150mm deep stud wall, very confusing!

It can be confusing. The regulations are fairly broad in their wording of requirements on some things, which leads to different interpretations of what complies.

There may also be different people who prefer to work one way as they find it easier for them.

It's worth having the conversation and asking why when requesting a quote - any reasonable electrician should be prepared to explain or discuss the questions you have if they want the work.

There are things that can only be done a certain way which aren't always obvious, but there are also often multiple ways to achieve an installation that complies.

The isolation switches in a cupboard comes down to what is considered 'easily accessible' - as some people consider a cupboard to not be - especially if it is full of stuff when the need arises to turn off the hob in an emergency. That may be down to a personal judgement call by the electrician involved.

Not entirely sure on the metal "back boxes without plastic plugs" you mention, could you explain that one further? The choice of back box usually comes down to what's easiest in the wall it's going into - plastic for plasterboard, metal for masonry walls. Plastic sockets are acceptable anywhere that sockets are acceptable though...

There are certain safe zones where a cable has to be run (relating to where the accessories are placed, corners etc), but certainly nothing specifically that says they can't be run in a 150mm stud wall. Are there other water, gas or heating pipes in the way perhaps, as they have to be kept separated from electrical wiring.

At the end of the day, don't go with an electrician that you aren't happy with - and that means one who is prepared to give answers that you can accept to questions you have.

 

[Dave OCD]

The refusal to use plastic wall plugs to fix metal accessory boxes to solid walls in a kitchen is ridiculous, a wild misinterpretation of the regulations I'd say.
And I'd be delighted to have the option to run cables and install boxes in a stud wall, quicker,easier and much less mess.

 

[snowhead]

Does the;
One has suggested that he has to fix metal back boxes without plastic plugs but instead use expensive fixings.
Refer to fixings in the stud wall or all fixings for all boxes?

 

[Dartlec]

The refusal to use plastic wall plugs to fix metal accessory boxes to solid walls in a kitchen is ridiculous, a wild misinterpretation of the regulations I'd say.
And I'd be delighted to have the option to run cables and install boxes in a stud wall, quicker,easier and much less mess.

I hadn't read that as wall plugs - if that is indeed the issue then maybe a misreading of fire rated fittings etc? Pretty sure that never applies to socket back boxes that are in a wall, but only cabling that is surface mounted (or in plastic surface trunking)

 

[nicebutdim]

The refusal to use plastic wall plugs to fix metal accessory boxes to solid walls in a kitchen is ridiculous, a wild misinterpretation of the regulations I'd say.

Even if a spark didn't want to use plastic plugs it would hardly be worth mentioning, considering the couple of £ it might add. Negligible difference in cost of overall works.

 

[Dave OCD]

I just think our trade is becoming infested with more idiots as time goes by. ?

 

[nicebutdim]

I just think our trade is becoming infested with more idiots as time goes by. ?

I'm optimistic about adding to that infestation soon ?

It does seem like an over zealous application of regulations, given that wall boxes and cables plastered into walls are never going to represent a hazard from premature collapse - I blame Youtube.

 

[Dave OCD]

Pedantry at its best [Or worst...] ?

 

[Dustydazzler]

Get a 4 th opinion / estimate

 

[brianmoooore]

Is the 150mm stud wall to be filled with insulation?

 

[sinewove]

Is the 150mm stud wall to be filled with insulation?

If sockets not allowed in cupboards,where would you fit them on islands or peninsulas?
S

 

[Anya32]

Thank you all for finding the time to give me advice, it's much appreciated.
To answer your questions, the metal back boxes are into masonry and it struck me as odd that there was a rule about using plastic plugs, I did ask for an explanation and that was that in a fire they would melt??? The 150mm stud wall will have acoustic Rockwool in the cavity but the electrician said that he could run the cables within 150mm of the floor, so you can see why I'm confused.
As suggested, I think I will get yet another quote.

 

[brianmoooore]

but the electrician said that he could run the cables within 150mm of the floor, so you can see why I'm confused.

150mm figures in the definition of several of the 'safe zones', but there is NOT a safe zone running horizontally up to 150mm from the floor.
If the cable is run in the middle of 150mm thick wall, then it doesn't need to in a 'safe zone', as it is considered (not by me) to be deep enough to be safe anyway, but if the wall is insulation filled it severely derates the current carrying capacity of the cable. The cable can be increased in size to counter this, of course, but it's best to avoid running a cable totally surrounded by insulation if avoidable.
The non plastic wall plugs for boxes is one of the most ridiculous things I've ever read on here. Total nonsense, told by someone who is either a crook or clueless.

 

[Dartlec]

Thank you all for finding the time to give me advice, it's much appreciated.
To answer your questions, the metal back boxes are into masonry and it struck me as odd that there was a rule about using plastic plugs, I did ask for an explanation and that was that in a fire they would melt??? The 150mm stud wall will have acoustic Rockwool in the cavity but the electrician said that he could run the cables within 150mm of the floor, so you can see why I'm confused.
As suggested, I think I will get yet another quote.

I think you have good reason to be confused, and would certainly suggest getting another quote - and raise some of these questions with them to be sure you are happy with their response.

The plastic plugs issue is simply not an issue in masonry walls with back boxes when relating to fire, even on the most stringent interpretation of recent regulations around premature collapse of cables in a fire. (though even if it were there are screws that would avoid it and cost pennies) - it sounds more like a reason to add a little to the quote....

There are safe zones within 150mm of corners, but NOT the floor (for cables buried in the wall), so not entirely sure what was being suggested by that electrician. Unless he was suggesting surface mounting on the wall where it would be behind kitchen units...

150mm up from the floor is very much NOT a safe zone because of the likelihood of skirting boards being nailed or screwed into the wall at a future point!

Insulation can affect a cable's rating to the point where a larger cable may be needed, but that's a fairly simple calculation which any electrician should be capable of doing....

It sounds like you've been unlucky but it's worth persevering to get a quote from someone who does know what they are talking about....