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Topic Title: Where is 25 year rule for rewire specified.?
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Created On: 31 January 2011 12:33 AM
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 31 January 2011 12:33 AM
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Evening all,
Had request to PIR an ex council house that is having a redevelopment grant allocated to it for various work.
The current occupier has been in 40 years and it was rewired at end of 70's.
There are cpc in switches and drops. Most sockets are surface mounted.The 3036 board is in great nick.PVCcable through out.A combined IR of over 20M, no main bonding or supp bonding.
At this point, I postponed my inspection and testing to fact find where this suggestion is noted.
I did not want to state to the council that it needed a rewire cos of the age without hard fact or reference to a reg otherwise I may have come across as a con merchant.
Normally I can make an educated decision on whether it should be rewired or not but this property is in good condition except for bonding and so could issue a satisfactory report upon addition of bondings.
Is the 25 year rule a reg or an NIC\ECA suggestion.
I personally would like to see RCD protection added as a minimum requirement and can justify that but where is the 25 years come from.
 31 January 2011 01:04 AM
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Where did you hear that?
Most of the time if i see an installation that has made it that far, it has had so many alterations and bodge ups done to it that it could do with a rewire.
In exceptional circumstances, a house that hasnt been messed with will be immaculate, and not require anything other than a cu change and updating of accessories.
When we do council grant work, this is what they ask for to be done. If the IR is ok, why rewire it?

The only time i would suggest a rewire before its time is up is if the customer is spending loads on rebuilding the house, and its a now or never situation.

Lack of planning on your part doesn't make it an emergency on mine....

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 31 January 2011 07:19 AM
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The 25 year recommendation was what we used to use in the 60's as most installations were pre-war, VIR singles or TRS twin/twin & earth. The usual clincher was when you took a light switch off and found the bare wire surrounded by crumbling insulation.
Hence 25 years. For plastic insulation, heat and teeth are the main dangers - not time.

 31 January 2011 07:54 AM
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Check the CPC size on ring finals. If it is undersized, a rewire may be an idea, otherwise RCD suggestion.
If you change the consumer unit the tennant will be upset when he now has to reset an MCB every time a lamp goes where previously there wasn't a "problem". Remedy this by putting low energy everywhere, and if CFL the warm-up time will be a disapointment!
Other than Bonding, there may be nothing urgent as such other than RCDs.

Richard (Dick)

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 31 January 2011 10:20 AM
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There isnt one that I know other than 25-30yrs will be a cable manufacturers specified life but that will be at the cable rating... use same principles as all PIRs.. suitability for continued service based on I&T....

In your case I would as a bare minimum recommend main bonding and front end RCD to avoid messy supplementary bonding, but if easy to do stick the sb in anyway... dependant on issues within the house... but make that secondary to a CU change with main bonding done as a recommendation only.
fail on bonding and supplementary bonding with rec2 and RCD front end with main bonds as remedial work as a minimum....

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 31 January 2011 10:00 PM
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Thanks for the comments as there are some good pointers .
I suggested to the 'grants man'that I could fit a cu which would entail an inspection and test.If any major things revealed themselves then a decision to rewire could be made as the difference of cu and bonding upgrade to rewire is £2000 difference.
I have been informed because the house has some disabled people in it there are 3 grants issued which is to cover new bathroom and a stair lift.
This, as Pete has said, is the reason the grant man has said to quote for rewire as a lot of money and work will be done so do all at once.
Thanks again
 31 January 2011 10:34 PM
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I think the 25 year recommendation comes from CIBSE!

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