i have this old thatched cottage with wiring in the roof to supply bedroom lights that mice have had a chew at i am considering rewiring these runs in armoured cable and utilising boxes over the light fittings . it has all been certificated but with these chew marks i am not happy relying on rcds obviously truncking is another option any sujestions or advice
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roof wiring?
- Thread starter big888
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DaveBrigg
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Mousetraps?
RCDs have no effect on L-N fault currents, and these will start fires very well.
Pyro is the one thing I'd recommend for this, aka MICC. It must be used with the appropriate accessories, and is best kept off RCDs where possible as it can get a bit leaky electrically. MICC is a copper pipe with the conductors inside bedded in MgO. It is rated for use in fires, but is also the most fire-starting-resistant cable there is.
The lower the fuse/mcb rating on a cable, the better the fuse is at clearing fault currents.
http://wiki.diyfaq.org.uk/index.php?title=Rewiring_Tips
NT
Pyro is the one thing I'd recommend for this, aka MICC. It must be used with the appropriate accessories, and is best kept off RCDs where possible as it can get a bit leaky electrically. MICC is a copper pipe with the conductors inside bedded in MgO. It is rated for use in fires, but is also the most fire-starting-resistant cable there is.
The lower the fuse/mcb rating on a cable, the better the fuse is at clearing fault currents.
http://wiki.diyfaq.org.uk/index.php?title=Rewiring_Tips
NT
i was amazed at the sparkys view that looked at the roof wiring i am a automotive electrical specialist and just bought this house and with the new regs etc i got him to install a simple ring for the kitchen and replace the small consumer unit and whilst he was here i wanted the roof looked at which he insisted the consumer unit would take care of any problems.The small amount of work done several thousand pounds was removed from my pocket. so now i will do the nec work my self, i have just installed electrics into the workshop now it is roof time at present the lights ar on 6ma mcbs and where do you sujest for suitable cable is armoured out of the question and what is ilike to use .as i write this 3miles away a thatch has just gone up in smoke!!!!!
Penners
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If you're going to do electrical installation work yourself, are you a "competent person" as specified in Part P of the building regs?
If not, then you'll have to get your work certificated by a building inspector, which will cost you a fee.
If not, then you'll have to get your work certificated by a building inspector, which will cost you a fee.
Nemesis
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But - no matter how good you are, the regs definition of a 'competent person' to work on house electrics might not include you!
Crazy but...
Crazy but...
big888 said:at present the lights ar on 6ma mcbs
6A MCBs are almost ideal, not worth changing.
and where do you sujest for suitable cable is armoured out of the question and what is ilike to use
You can use whatever you want. But for fire resistance I'd recommend pyro. If you've not used it before you need to read up how to terminate it correctly.
Good to see people sorting their houses out and making the dangers safe.
NT
Lime
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The problem with pyro is that it's difficult/impossible to terminate into standard ceiling roses and switches without using conduit boxes to terminate into.
It requires a good deal of skill to do too.
If conduit boxes are needed then why not use steel conduit with PVC/PVC cable throughout?
It requires a good deal of skill to do too.
If conduit boxes are needed then why not use steel conduit with PVC/PVC cable throughout?
Penners
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Quite right. You have to be officially certificated.Nemesis said:the regs definition of a 'competent person' to work on house electrics might not include you!
Note that I didn't say "certified". That's different. :wink:
hi yes i know all about the legal side of things but as i mentioned before . but i am the one who has to sleep at night and i have used the correct channel previously and i am not happy with the wiring.i have thought about pvc inside conduit which is probably the safest from rodents. but the logistics of it is another because the house is circ 1660, when the thatch was done around 15 yrs ago cables were laid under the thatch and some cable dropped down between the beams . so i think at present it may mean cutting out what i am not happy with and fitting various junction boxes etc and now i have another problem up in the roof wasps have moved in
DaveBrigg
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With luck, the wasps will keep the mice away. QED
Lime said:The problem with pyro is that it's difficult/impossible to terminate into standard ceiling roses and switches without using conduit boxes to terminate into.
Proper materaisl & methods should be used as they prevent ingress of damp into the cable. MICC's one weakness is it is hygroscopic, so terminating it into a domestic lighting rose is not recommedned.
NT
Lime
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MICC's one weakness is it is hygroscopic
Yes but isn't it strange that no other design of termination has been produced?
I would have thought that there was a market for a slimmed-down version, doing much the same job but with a smaller diameter, perhaps with a screw seal rather than the crimp as at present.