Rat chewed wiring

[trevw]

Hi,

the upstairs lights recently started blowing their fuse (old style fuse wire), on investigating in the loft (fully boarded but with a hatch for wiring access) it seems some rats have taken a liking to the insulation on the wires around the central lighting connection centre.

Some of the wires are so badly chewed that a large amount of copper is showing and in one case touching (hence the blown fuses).

I have been told that once Rats get into a row of terraced houses like mine it can be very hard to get rid of them. The circuit is now off (fuse removed) and I am trying to contact an electrician and an exterminator..

Obviously I will be talking through my options with the electrician, but I have had trouble getting hold of him.. (holiday season I guess) What can I expect? It seems to me that if there is one badly chewed area then there could be others that I can't see.. am I looking at having all of the boards up and all the wiring replaced or can the wiring be otherwise tested/inspected? The upheaval required to remove all of the loft boarding will be immense.. Also once this is done, what is to stop the Rats 'attacking' again, will the wiring all have to be in trunking or something?

fortunately at this time of year upstairs lights are not crucial but it would be good to get this sorted fairly quickly..

thanks for any thoughts

Trev

 

[PrenticeBoyofDerry]

Obviously you will need to replace chewed wires.
I would expect the electrician to test for insulation resistance, between all conductor of the circuit, this can be done without any upheaval of the loft boards. This test will give readings on the state of the insulation between the conductors and whether it is within the required range. If the test fail then further investigation will be required and loft board removed accordingly.
It may not just be your lighting circuit they have attacked but any power circuit accessible to them.
So you need to get rid of the rodents, I would start with rat pellets/poison!
Then if this is a continued problem, preventative measures regarding cable protection should be made, such as conduit/trunking. But if you do use conduit/trunking on power circuits be aware that this can effect the cable current rating and upgraded cable sizes may be required.

 

[JohnW2]

Obviously you will need to replace chewed wires. I would expect the electrician to test for insulation resistance, between all conductor of the circuit, this can be done without any upheaval of the loft boards. This test will give readings on the state of the insulation between the conductors and whether it is within the required range. If the test fail then further investigation will be required and loft board removed accordingly.

I must say that, if it were my home, and if there were evidence of chewed wires (possibly some under boards), I would want to expose and examine those cables, rather than derive 'reassurance' (and hence not lift boards) if IR measurements were OK. I've seen cases in which insulation had been chewed away to the extent that significant lengths of all conductors were totally exposed, but hadn't yet touched - but just waiting for the slightest movement (rodent-induced or otherwsie!) to create a potentially major problem.

Kind Regards, John

 

[phatboy]

Sounds like a possible house insurance claim to me? In which case push for someone else (electrician) to lift the boards to inspect and repair as necessary.

 

[Mursal]

I can see the electricians lining up around the block, to lift floor boards in an attic with rodent damage.

So don't be to surprised if a few go missing, like on holiday

Bait blocks nailed to an old piece of timber and keep replacing until uneaten

http://www.ebay.co.uk/itm/48-All-we...ants_Weed_Pest_Control_CV&hash=item19d1d41250

Good luck

 

[PrenticeBoyofDerry]

I must say that, if it were my home, and if there were evidence of chewed wires (possibly some under boards), I would want to expose and examine those cables, rather than derive 'reassurance' (and hence not lift boards) if IR measurements were OK. I've seen cases in which insulation had been chewed away to the extent that significant lengths of all conductors were totally exposed, but hadn't yet touched - but just waiting for the slightest movement (rodent-induced or otherwsie!) to create a potentially major problem.

I cannot disagree with your statement John and it would be the best and my proffered option also.

 

[martinxxxxxx]

On the rat problem - really don't start poisoning them - they die and rot all over the place and you do not want the smell of dead rat everywhere (trust me!)
I know everyone is going to shoot me down for saying this but "get an expert in"

As for the electricians being scared of rat poo - occupational hazard, there is no escaping it; not when 60% of my work is in student properties.

 

[JohnW2]

I cannot disagree with your statement John and it would be the best and my proffered option also.

Indeed. I think there is a tendency for some (hopefully not many!) electricians to put too much faith in what they can measure with their clever test equipment without stopping to think enough about what potentially dangerous horrors might exist which won't be detected by such methods - i.e. they don't give as much weight as they should to the 'Inspection' part of 'Inspection and Testing'!

Kind Regards, John

 

[xr4x4]

If you get the proper stuff, it dehydrates them, drys their blood out.

First thing they want to do is escape to water to drink, if they don't they die dryed up and don't smell.

 

[martinxxxxxx]

If you get the proper stuff, it dehydrates them, drys their blood out.

First thing they want to do is escape to water to drink, if they don't they die dryed up and don't smell.

Right

 

[JohnW2]

If you get the proper stuff, it dehydrates them, drys their blood out. First thing they want to do is escape to water to drink, if they don't they die dryed up and don't smell.

Hmmm - I wouldn't put any money on the relaibility of that theory! Even 'dried up' animals tend to stink when they rot! ... and, anyway, even if seriously dehydrated, they are far from 'dry'/bloodless!

Kind Regards, John.

 

[xr4x4]

If you get the proper stuff, it dehydrates them, drys their blood out.

First thing they want to do is escape to water to drink, if they don't they die dryed up and don't smell.

Right

Lol..

They look like old plastic dog chews after..!

 

[PrenticeBoyofDerry]

On the rat problem - really don't start poisoning them - they die and rot all over the place and you do not want the smell of dead rat everywhere (trust me!)
I know everyone is going to shoot me down for saying this but "get an expert in"

Who will leave poison for them!

 

[PrenticeBoyofDerry]

Indeed. I think there is a tendency for some (hopefully not many!) electricians to put too much faith in what they can measure with their clever test equipment without stopping to think enough about what potentially dangerous horrors might exist which won't be detected by such methods - i.e. they don't give as much weight as they should to the 'Inspection' part of 'Inspection and Testing'!

I recall an I&T I did in April where the client had requested a CU change and I tested out the lighting circuit reading >299MΩ but the insulation on the bathroom ceiling light was totally shot at! So always worth a little investigation.

 

[JohnW2]

I recall an I&T I did in April where the client had requested a CU change and I tested out the lighting circuit reading >299MΩ but the insulation on the bathroom ceiling light was totally shot at! So always worth a little investigation.

I see it in all sort of fields, many highly divorced from matters electrical. I'm afaraid that some people have become so focussed on their high-tech gizmos that they fail to use their eyes and common sense. Technology is a useful aid, but it should not come to be regarded as a panacea, or a substitute for common sense!

...one sees some frightening examples on 'Air Crash Invesigation'. Some modern-generation pilots will believe the high-tech displays telling them that their plane is not stalling in a situation in which it would be totally obvious to any 'seat-of-the-pants' pilot that it was stalling!

Kind Regards, John.