Messy wires in loft - rewire, splice, or derate?

[hello1kitty1]

I am going to insulate my loft, but the wiring up there is a complete mess!

I have lots of wires with no slack, cutting diagonally over the joists some through them. I also have wires clipped running along the joists.

I really want to put insulation down between the joists, but know you're not supposed to cover wires with insulation.

What are my options? I've thought of:

1. Asking an electrician to rewire the whole home, and putting the wires on the rafters (will the cold affect them? I am only insulating the floor).
2. Asking the electrician to cut the wires in the middle, bring them up off the joists and add 2 large junction boxes with extra wiring in the middle
3. Tempt fate and insulate over them (I've read something about "derating"?)
3. Give up and wear socks.

Any thoughts appreciated!!!

 

[deadshort]

I would rewire.

DS

 

[John D v2.0]

I'd rewire too, but I guess the op wouldn't do it himself so cost would be higher.
Op, if the cable is 1.5mm² and protected by a 6A mcb then insulate away. If not there may technically be heat issues.
Our upstairs lighting circuit was ostensibly connected to a 15A fuse wire, and was covered in isolation, and everything survived. However I wouldn't want to find out what would happen in a fault situation. I changed to a 6A MCB.
I say ostensibly because the actual fuse wire looked more like a piece of CPC.

 

[endecotp]

You need to work out what all the wiring is.
You might find that a lot of it is related to recently-added (i.e. last decade or so) multiple spotlights - spaghetti-wiring seems to be the norm for them! But it can probably be tidied up relatively easily.

 

[ban-all-sheds]

Op, if the cable is 1.5mm² and protected by a 6A mcb then insulate away. If not there may technically be heat issues.

If it's a 6A lighting circuit, 1.0mm² would also be fine.

Shower and socket circuits are the potential problems.

 

[hello1kitty1]

Thanks. It looks like it's all live and related to the flat. Mix of 2.5mm and 1.5mm, as well as a 6mm going to the oven.

If we get a rewire done:

1. Can electric wires go across the uninsulated rafters, or are they negatively impacted by the cold?
2. For power sockets in solid walls, does this mean the electrician will be chasing out all our brickwork again, or are there usually "pipes" in walls so they can just replace the wires?

 

[endecotp]

No problem with wires being "too cold".
There are various different ways that wires can be run in walls. If you're lucky there will be no need to touch them.