Wiring in the loft of a thatched house

[yellowvanman]

Fairly new thatched house (less than 10 years old), owner wants some sockets put in the loft for an aerial booster.

All existing cables are twin and earth enclosed in a 16mm conduit! The conduit ends just above where a cable enters a room or stud wall, with maybe 20mm or so of cable exposed. My guess is that this is to provide protection against rats/mice etc. However its a new property and unlikely to have that problem.

The problem I have is that customer wants me to add cables in the same way - but I'm thinking that the existing conduit should be earthed and its not! Also haven't found a source for this size of conduit.

Any thoughts on this?

 

[cbw]

I avoid all thatched cottages!

Need mechanical protection in loft space, cant remember reg nos but did check this fairly recently for PIR purposes.

Pain in rear and every time news reports of thached cottage on fire.........argh....no thanks!

 

[JD6400]

We do this in property's that have received squirrel damage but in armoured copex into 4x4 metal adaptable box's fixed directly above any drops / lights .
We have found in the past that as soon as they get a taste for t+e the little buggers seem to come from all over and are very difficult to control / get shot of ?

 

[sjm]

Check out this reducer. www.cmcne.co.uk/conduit.../steel-conduit-reducer-20-16mm-p548. It might help.

 

[yellowvanman]

Need mechanical protection in loft space, cant remember reg nos but did check this fairly recently for PIR purposes.

No there isn't a specific reg in BS7671 that requires mechanical protection in thathced lofts - you just have to way up the risks - if I had seen mouse poo etc then I would put in mechanical protection. I've also read an NICEIC paper on this and all they say is may need this and may need that - never black and white!

Its all very well saying this for lofts but I've also seen fauna damage in the cables under the floorboards.

I think my plan maybe is to use 'pre-wired' conduit (cable to BS8436) not rodent proof but if they do nibble then more than likely to trip out the circuit!

What about lack of earthing for the existing conduit?

 

[yellowvanman]

Check out this reducer. www.cmcne.co.uk/conduit.../steel-conduit-reducer-20-16mm-p548. It might help.

thanks but I don't think the existing 16mm conduit is steel - more lightweight - and there certainly isn't any threaded ends - elbows are held in place with a 'jubillee clip' type mechanism

 

[cbw]

I am just a coward................

I am sure its covered under the old flaura and fauna and it is not unusual for most of the cottages round here to be wired with trunking/conduit.

 

[Richard Burns]

Insurance companies often want the wiring protected against rodent chewing, though I notice for yours they have kindly left a space for the mice to easily reach when coming up to the cable!
They often want smoke alarms in the loft as well.
If the conduit is PVC conduit, you could easily slip 20mm over the 16mm and continue that way.

 

[jase]

why not just use SWA?

 

[SimpleSimon]

What about lack of earthing for the existing conduit?

So how does it enter the consumer unit?Is the conduit thread into.a metallic conduit? It should be earthed in my mind, but it seems strange that a new house has gone to all the effort with the conduit....yet havent earthed it??

Sent from my GT-I9100 using Tapatalk

 

[UKMeterman]

Hi,
Where is the TV distribuion amp? Some better quality amps come in two parts, you send 12V dc on the coax from a convienit point (not in loft) and the amp is a seperate part you could put in the loft powered via the coax.

 

[yellowvanman]

Answers some questions raised:

Why not use SWA? - nothing to gland into that is readily accessible
Entering the consumer unit? Consumer unit is on the ground floor, conventional T&E earthing throughout house. In the loft T&E enclosed in this conduit.
TV amp position? - in loft already supplied and in position being temporarily fed by an extension lead.

 

[UKMeterman]

Have a lookat Screened Variable Masthead Kits | Antiference this bit sits in the loft and a 12v supply sits behind a telly