Loft light from powered smoke alarm

[amcaskie]

Hello

Our (2yo) house has loop in switch wiring for all the lighting, with separate circuits for upstairs and downstairs. I'd like to install a single fluorescent light into the loft, and my starting assumption has been to feed this via a switched spur from the live feed and neutral choc bloc in any one of the upstairs light switches.

However, I find it hard to get three wires secure in the COM position on a light switch (loop-in, loop-out and feed to loft) so to avoid this and the hassle of fishing cable down the wall, I wondered if it might be ok to feed the new loft light as a spur off the spur already in the loft that feeds the landing smoke alarm.

I know that adding a spur to a spur is dangerous in power sockets, but does this rule apply (or is it best practice to avoid) for lighting circuits?

Many thanks for your help.

Andy

 

[GaryMo]

A lighting circuit is a radial which can be extended though conditions apply to how far and how much extra loading may be added.

Is the smoke alarm fed from the upstairs lighting circuit?
If so then as long as you're not overloading the circuit by adding an extra fitting then I can't see why you can't do as you suggest.

 

[amcaskie]

Thanks for your quick reply.

Yes, smoke alarm definitely fed from upstairs lighting circuit.

Thanks again.

Andy

 

[Taylortwocities]

Your OK to go, then!