Bungalow Loft Insulation - Electrics (again)

[bmouthboyo]

I know this has been covered a great deal but just wanted to run my thinking past you guys.

So the property I have moved into is an old 1070's bungalow and the insulation is the loft is pretty poor and thin in places so would like to get this as good as I can and near 270mm.

I am aware regulations state the wiring capacity is downgraded when inside the insulation. My current setup is mostly on slightly raised planks:

I am thinking the easiest safe route is to insulate up to these and under where possible with slight compression of insulation but not over. For the wires that go off these I was thinking some kind of trunking, is this acceptable? Any recommendations of easy to fit shroud type trunking which would allow me to then put insulation over the top?

Thanks

 

[OwainDIYer]

Before you insulate over those junction boxes you need to get them looked at by an electrician as earths should not be outside the box joined by terminal strip. A close-up of the j.b. would be interesting. You may also have other electrical issues which require attention.

Lighting cables are usually fairly generously sized. The ones you need to be careful of are any immersion heaters on 1.5mm (or imperial equivalent) cable, and electric showers.

 

[endecotp]

If the cable is in contact with a joist on one side and insulation on the other, its current-carrying capacity is not reduced as much as if it is surrounded on all sides by the insulation.
In a loft, much of the wiring is often for lighting; lights don't take much current and the wiring is often much thicker than necessary.
These two factors mean that you may not need to worry much. But you do need to know what all the wires do, and how thick they are, first.

I agree a closeup of the junction box and surrounding terminals would be interesting. Mostly it looks neat but....

 

[bmouthboyo]

Before you insulate over those junction boxes you need to get them looked at by an electrician as earths should not be outside the box joined by terminal strip. A close-up of the j.b. would be interesting. You may also have other electrical issues which require attention.

Lighting cables are usually fairly generously sized. The ones you need to be careful of are any immersion heaters on 1.5mm (or imperial equivalent) cable, and electric showers.

Out of interest how should the earths be wired? Inside the junction box's or using insulated wire etc?

 

[OwainDIYer]

They should be wired to a terminal inside the junction box, with green/yellow (was green) sleeving. Your bungalow must be very early 1970s as I think green sleeving was used until 1977.

 

[bmouthboyo]

They should be wired to a terminal inside the junction box, with green/yellow (was green) sleeving. Your bungalow must be very early 1970s as I think green sleeving was used until 1977.

Is it a DIYable job to replace redo the earths or must it be done by a sparky??

 

[endecotp]

Like most such questions, it would depend on your competence.
A closer photo would be interesting.