Steel Wire Armoured Cable and ceiling roses

[riveralt]

Got a customer who wants to add an additional ceiling rose in their kitchen effectively linking the current light - no problem there then.

However, he doesn't want me lifting the floorboards in the bedroom above and of course the ceiling beams run in the wrong direction.

The kitchen is going to have a upvc ceiling fitted creating a gap between the old and new ceiling of approximately 25mm and this presents an opportunity to run cable from the current ceiling rose to the new one.

There is no rcd protection the lighting circuit.

Because the cable will not be buried more than 50mm from the ceiling will I have to fit 3 core SWA - Line, neutral and earth.

And if so, what's the best way (if there is one) to connect the SWA to the old and new ceiling roses?

 

[1john]

cut a strip of plasterboard out of the existing ceiling if it is being over boarded and drill the joists.

 

[Adam_151]

25mm gap you say? hows this?....Remove ceiling rose, drill 20mm hole in back of 20mm galv end box, bush and locknut, mount over cables from ceiling, when ceiling goes back up, mount rose to box with brass m4 bolts, remember to earth besa box... I'd probably go for a length of galv rather than SWA though

 

[Adam_151]

cut a strip of plasterboard out of the existing ceiling if it is being over boarded and drill the joists.

Thats the best way, although I assumed the owner had refused to let him do this, "what if I take the ovc ceiling down in 10 years..." so thats why he was asking about swa

 

[1john]

if it comes down in ten years it will be peppered in holes and need a re skim anyhow, so patching up some plasterboard wont make a big difference.

 

[riveralt]

Thanks for the speedy and interesting replies.

cut a strip of plasterboard out of the existing ceiling if it is being over boarded and drill the joists.

I'll try and persuade the customer - failing that I might go down the RCBO route

 

[RF Lighting]

Whats wrong with pyro?

 

[RF Lighting]

failing that I might go down the RCBO route

What RCBO route?

 

[Lectrician]

If you trash the plasterboard to drill the joists, you will need to re-board to bits you remove to retain the fire rating - your PVC cladding will not be a fire barrier.

Galv term boxes with a length of steel conduit is the cleanest way.

 

[riveralt]

failing that I might go down the RCBO route

What RCBO route?

The Circuit is MCB protected but the CU will take an RCBO @ £30 this might be the quickest and cheapest option.

Doing it this way should comply with 522.6.7 given I would breach 522.6.6

 

[ColJack]

what's wrong with a bit of alitube?

 

[RF Lighting]

failing that I might go down the RCBO route

What RCBO route?

The Circuit is MCB protected but the CU will take an RCBO @ £30 this might be the quickest and cheapest option.

Doing it this way should comply with 522.6.7 given I would breach 522.6.6

When did a ceiling become a wall or partition?

Regulation 522.6.5 is the one youre after

There is no RCD get-out clause for <50mm above a ceiling.

 

[ColJack]

522.6.5 A cable installed under a floor or a bove a ceiling shall be run in such a position that it is not liable to be damaged by contact with the floor or the ceiling or their fixings. A cable passing through a joist within a floor or ceiling construction or through a ceiling support ( e.g. under floorboards ), shall:

(i) be at least 50 mm measured vertically from the top, or bottom as appropriate, of the joist or batten, or

(ii) incorporate an earthed metallic covering which complies with the requirements of these Regulations for a protective conductor of the circuit concerned, the cable complying with BS 5467, BS 6346, BS 6724, BS 7846, BS EN 60702-1 or BS 8436, or

(iii) be enclosed in earthed conduit complying with BS EN 61386 and satisfying the requirements or these Regulations for a protective conductor, or

(iv) be enclosed in earthed trunking or ducting complying with BS EN 50085 and satisfying the requirements or these Regulations for a protective conductor, or

(v) be mechanically protected against damage sufficient to prevent penetration of the cable by nails, screws and the like.

 

[riveralt]

failing that I might go down the RCBO route

What RCBO route?

The Circuit is MCB protected but the CU will take an RCBO @ £30 this might be the quickest and cheapest option.

Doing it this way should comply with 522.6.7 given I would breach 522.6.6

When did a ceiling become a wall or partition?

Regulation 522.6.5 is the one youre after

There is no RCD get-out clause for <50mm above a ceiling.

I believe the 25mm gap between the original ceiling and the new plastic ceiling could count as a partition in a similar way that a studwall would be a partition the only difference is the size of the gap.

I couldn't find a specific definition is the regs for a 'partition'.

It is odd that 522.6.5 doesn't give the RCD get out since it would improve safety. Perhaps, heaven forbid, the IEE made an error

 

[electronicsuk]

what's wrong with a bit of alitube?

Yup. Alitube will get you out of this situation easily, with no grey areas as to the definition of a partition and whether or not the cable run is compliant. You might have to get friendly with someone who has a few metres to spare, though, as I don't know if it's easy to get hold of without buying bulk.