Confused with so many rules

[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....

 

[brianmoooore]

We must have started writing at almost the exact same time, but my post is shorter, so I got in first!

 

[Dartlec]

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.

Let's not rule out both!

 

[Anya32]

Thanks for the clarification guys. Much appreciated x

 

[Pete999]

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.

Anya32 to be honest you need to get an Electrician with lots of experience, not some chancer that hasn't any common sense, that is, as already mentioned a crook trying to up the price, baffling someone "no criticism of yourself" that has very little or no experience of electrical installation work, out of interest what fixings did this Herbert recommend using to fix the boxes to the wall??, good luck, post your location, a member may be able to help you out.

 

[telectrix]

OPis in Bury.st. Edmunds.