aluminium wiring

woodsta · Feb 2, 2011

i have been asked to carry out a periodic report on a 1960s house, apparently the wiring is still all original so i am concerned there may be some aluminium cable in the installation if so what code should this be or should it just be replaced? i mentioned to the owner that the house should be rewired every 25 yrs but there not keen on the expense. so is there any way the aluminium is acceptable?

telectrix · Feb 2, 2011

first, make sure it's not tinned copper. if it is aluminium, it's prone to fracture and considering it's age, IMO should be replaced. you can't force them to have a rewire though, if they won't go for it, note it on your PIR. it's debateable whether or no --- would deserve a code1.

woodsta · Feb 3, 2011

thanks i will be doing the remedials so what would you suggest i do if i find aluminium cable at sockets? the owner will be renting rooms out

Deleted member 9648 · Feb 3, 2011

As long as all the tests are ok on alu wiring and it appears in good condition it's debatable whether it should be coded at all.
That said there is one 70's estate near me almost all alu and there are always problems with breaks in ring continuity etc.It is liable to break down at any time,especially if disturbed.....for that reason as Telectrix has said I would probably code it......... 2 even if tests are ok.
My advise is if you find alu is to carry out the inspection with as little disturbance as possible,as pulling points off for inspection is bound to result in problems.Note the limitations on the cert.

nickblake · Feb 3, 2011

Totally agree with wirepuller and telex on this one ,but would recommend it be replaced due to the fragile nature of the cable especially if its supplying large loads cooker shower etc where if a fault does occoure it could cause a fire better safe than sorry thats what id say

rocker · Feb 3, 2011

It will almost certainly need replacing, however I'm not sure you'd be able to code it as it doesn't contravene BS7671 and was standard at it's time of installation. You could only really code it because of it's age and wear-and-tear if it's in bad nick. I may be wrong, mind.

Deleted member 9648 · Feb 4, 2011

One option here rather than code if it all tests out ok would be to recommend a shorter period between inspections....say 5yrs rather than 10..(for a domestic)...and state the reasons in your report.

Deleted member 26818 · Feb 4, 2011

Regulation 524.1 requires aluminium conductors used for power or lighting to be 16mm² or larger.
Regulation 543.23 requires protective conductors to be copper if 10mm² or less.

Deleted member 9648 · Feb 4, 2011

spinlondon said:
Regulation 524.1 requires aluminium conductors used for power or lighting to be 16mm² or larger.
Regulation 543.23 requires protective conductors to be copper if 10mm² or less.

Yes,but for the purpose of a PIR if they complied at the time of the install and are in satisfactory condition you cant really condemn them.

mogga · Feb 4, 2011

Are you SURE they are aluminium ?? as mentioned before Tinned copper stranded was popular in 60s

roukel01 · Feb 4, 2011

I might be wrong here, but I have never heard of aluminium conductors being used in domestic situations. Usually the UK only used aluminium (and still do) on larger supply cables, due to weight and the rising cost of copper.

Rubber cables wrapped in cotton cloth was about as early as 1922, and this had copper conductors that was tinted because Copper is very difficult to bare from rubber insulation.

Deleted member 9648 · Feb 4, 2011

In the early 70's there was a copper shortage and for a while PVC aluminium T/E cable was available and used. Some of this was copper covered alu....some was just plain aluminium. It is single strand and the conductors are slightly larger than the copper equivalent....it is horrible stuff and best not disturbed,as loose connections and broken wires at terminations are rife and a can of worms will be opened.
It feels totally different to old stranded copper,and is easily recognised if you have the misfortune to come across it.

Deleted member 26818 · Feb 4, 2011

wirepuller said:
Yes,but for the purpose of a PIR if they complied at the time of the install and are in satisfactory condition you cant really condemn them.

How much time do you allow to pass before deciding something that complied in earlier Regulations is now unacceptable?

Deleted member 9648 · Feb 4, 2011

spinlondon said:
How much time do you allow to pass before deciding something that complied in earlier Regulations is now unacceptable?

Thats the inspectors call....you have to decide whether the safety of the installation is compromised by the non-compliance.

Graeme Harrold · Feb 4, 2011

Just done a partial rewire to rid the property of al cable. If its still there, chances are it will be in a very poor state due to the interaction between copper accessories and the al cable. Also from memory, the aluminium equivelant carying capacity is lower as this was something else not noted at the time it was fitted, i.e. 2.5mm al was the replacement for 2.5mm cu!!! Have a good look round, and ask before removing an accessory, just let them see how bad it possibly is.