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Rewire in MICC.....
chewed circuit cables
- Thread starter 417welly
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Thought for a minute you had said
Rewire in MICE….
Rewire in MICE….
Yes, I'm sure that's what he meant but, as I said/implied, if one simply re-wired, without mechanically protecting the new cables and/or 'definitely' getting rid of the rodents, then there could be newly-damaged cables 'a day or three after' the rewire!
Having said that, one had to consider practicalities. Mine is a very large house and, on a couple of occasions over the few decades I've been here, I have become aware of rodent damage to cables - and, if I had undertaken a total re-wire on each occasion (in case there were unseen rodent damage to other cables) I would probably have needed a 'second mortgage'
Kind Regards, John
They can, but it's an important part of the equation, since 'e-wiring' alone is not enough.
Kind Regards, John
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I don't think anyone is saying to keep rewiring rather than solve the rodent problem, no one's hinted at that I'm sure.Yes, I'm sure that's what he meant but, as I said/implied, if one simply re-wired, without mechanically protecting the new cables and/or 'definitely' getting rid of the rodents, then there could be newly-damaged cables 'a day or three after' the rewire!
Having said that, one had to consider practicalities. Mine is a very large house and, on a couple of occasions over the few decades I've been here, I have become aware of rodent damage to cables - and, if I had undertaken a total re-wire on each occasion (in case there were unseen rodent damage to other cables) I would probably have needed a 'second mortgage'
Kind Regards, John
Probably not, but someone certainly suggested a re-wire without any mention/hint of the need to also solve the rodent problem (albeit perhaps because he thought that was 'obvious').
However, if there is to be a re-wire, it should obviously be preceded by solving the rodent problem..
Kind Regards, John
Yeah, i agree the rats have to go rather than trying to accommodate them! I'm hoping the problem is now solved. The house belonged to a horder, was full of nasty food sources which have now been cleared followed by a couple of months of putting down bait (which is no longer being eaten)
i'm actually pretty confident that i've spotted all damage as all the ceilings are down and have lifted some floorboards + there has been enough slack to pull through a bit either side to inspect where cables go through walls etc.
Regarding any repairs using connection boxes, what is meant by accessible?
i see there are existing junction boxes in ceiling voids so i'm assuming this is considered accessible even though you would have to remove flooring covers and floorboards once the house is finished?
i'm actually pretty confident that i've spotted all damage as all the ceilings are down and have lifted some floorboards + there has been enough slack to pull through a bit either side to inspect where cables go through walls etc.
Regarding any repairs using connection boxes, what is meant by accessible?
i see there are existing junction boxes in ceiling voids so i'm assuming this is considered accessible even though you would have to remove flooring covers and floorboards once the house is finished?
Unfortunately there is no definition in the UK* regulations of the term “accessible”..
In my opinion in a ceiling void is not accessible in any practical way. You may be faced with ripping up carpet to get at the thing. The floor may be finished with tiles, engineered wood, laminate etc meaning access is by pulling down the ceiling. Even if anyone remembers where the junction is hidden.
Back in the past there was no restriction on use of junction boxes (with screw terminals) and millions are installed where they cannot be reasonably easily accessed. A problem has been found with junctions using screwed terminals: over time the pressure of the (hard metal) screw terminal on the soft copper conductor reduces and can cause a high resistance joint. This can mean heating up, circuit failure, potential for fire…
This can happen over a long period of time. Years after you may have moved out. A future electrician -trying to find a fault - will not know if there are hidden junction boxes, or where they may be hidden.
So recent changes to the regs do not permit the use of these types of junction. They must be classed as “maintenance free”.
*EDIT. other jurisdictions do specify what accessible means. USA example:
https://www.electricallicenserenewa...ation-Courses/NEC-Content.php?sectionID=205.0
In my opinion in a ceiling void is not accessible in any practical way. You may be faced with ripping up carpet to get at the thing. The floor may be finished with tiles, engineered wood, laminate etc meaning access is by pulling down the ceiling. Even if anyone remembers where the junction is hidden.
Back in the past there was no restriction on use of junction boxes (with screw terminals) and millions are installed where they cannot be reasonably easily accessed. A problem has been found with junctions using screwed terminals: over time the pressure of the (hard metal) screw terminal on the soft copper conductor reduces and can cause a high resistance joint. This can mean heating up, circuit failure, potential for fire…
This can happen over a long period of time. Years after you may have moved out. A future electrician -trying to find a fault - will not know if there are hidden junction boxes, or where they may be hidden.
So recent changes to the regs do not permit the use of these types of junction. They must be classed as “maintenance free”.
*EDIT. other jurisdictions do specify what accessible means. USA example:
https://www.electricallicenserenewa...ation-Courses/NEC-Content.php?sectionID=205.0
Last edited:
... and that uncertainty will, of course, exist for decades to come, even if everyone started installing MF JBs when they should have done.
As an aside, whilst I obviously understand that what you say about "a problem has been found..." is theoretically true, and the official line, I have to wonder about the magnitude of this 'problem'. How often, I wonder, do electricians actually encounter this theoretical problem? For what it's worth, I have personally lived with countless screwed JBs for many decades, without any such problem ever having shown itself by 'consequences'.
On the other hand, I have, on a number of occasions, experienced issues due to loose screwed joints in situations in which they have been repeatedly 'unscrewed and re-screwed' in the name of 'testing', or in accessible accessories etc. which are sometimes replaced. It's therefore my personal experience (again, for what it's worth) that screwed terminals which are not 'disturbed' very rarely 'come loose'. I would therefore be interested to know of the experiences of electricians.
Kind Regards, John
Again, whilst that might well be theoretically true, I wonder how often problems due to this are actually seen in practice.
Kind Regards, John
I have had the screws come loose on the 12V halogen units I fitted a few years ago, quite a few have had multiple tightening.
That's true, but 'in the past' is a lot further away than most people might imagine.
Joints between flexible conductors and permanent wires were first required to be accessible in the 4th edition, published in 1903.
All joints were required to be accessible from the 5th edition in 1907.
Similar requirements have appeared in every edition since then, with the only real changes being that from the 15th edition some types of permanent connection can be concealed, and the most recent addition being the BS5733 MF connectors.
100% of the junction boxes found under floors and in similar locations do not comply and never did.
Anyone alive today who installed such things was doing it wrong.
I get the impression that in the past the "wiring regs" were often treated as little more than suggestions. Even today they aren't actually Statutory except in private rented accommodation. Electricians doing major works are now effectively forced to join a "competent person" scheme and I think those schemes tell their members to follow BS7671 but there is no such requirement for many smaller jobs.
And then as Taylor says there is the problem that BS7671 doesn't actually define accessible and that the accesibility of a location can change as a result of non-electrical works. For example both my property and my parents property have crawlspaces under the ground floor that can be accessed easily and even parts of the first floor at my parents property (my property doesn't have a first floor) are not too bad to access with screwed floorboards under easy to lift carpets. Other parts though have flooring that would be a major PITA to lift. Simarly at some point a bunch of chipboard got put down in my parents loft and i'm pretty sure there are JBs underneath, accessible when installed but not anymore. It would be easy for future works on the property to change a location that is relatively easy to access into one that was a major PITA to access, or for a future occupant to not know about the accesses that do exist.
I also think people are more willing to bend/break rules when they don't see a workable soloution that complies with the rules. Before the BS5733 boxes I suspect some people knew that they were stretching the rules by putting JBs in locations of questionable accesibility but did not see a better option.
And then as Taylor says there is the problem that BS7671 doesn't actually define accessible and that the accesibility of a location can change as a result of non-electrical works. For example both my property and my parents property have crawlspaces under the ground floor that can be accessed easily and even parts of the first floor at my parents property (my property doesn't have a first floor) are not too bad to access with screwed floorboards under easy to lift carpets. Other parts though have flooring that would be a major PITA to lift. Simarly at some point a bunch of chipboard got put down in my parents loft and i'm pretty sure there are JBs underneath, accessible when installed but not anymore. It would be easy for future works on the property to change a location that is relatively easy to access into one that was a major PITA to access, or for a future occupant to not know about the accesses that do exist.
I also think people are more willing to bend/break rules when they don't see a workable soloution that complies with the rules. Before the BS5733 boxes I suspect some people knew that they were stretching the rules by putting JBs in locations of questionable accesibility but did not see a better option.
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