What cables do I need

[AEM]

My plasterer has called to say he can turn up in a week's time, wasn't expecting him for another couple of months and don't want to turn him away but I still have hallway lighting cables to install. I don't rate my chances of finding an electrician in a week so will happy enough if I can just put the cables in place ready for plastering and when my electrician turns up he can fit the switches and commission. I am hoping a kind soul can tell me what cables i need to install between each of the following.

Downstairs hall - 1 pendant, 2-gang switch for hall light and 1st floor landing light, 1-gang switch for hall light
1st floor landing - 1 pendant, 3-gang switch for downstairs hall light, 1st floor landing light and 2nd floor landing light
2nd floor landing - 1 pendant, 2-gang switch for 1st and 2nd floor landing lights

A circuit is currently coming from consumer unit to downstairs pendant light. No other cables are installed but I have a roll of 1.5mm twin and earth and a roll of 3-core and earth ready to go. I have read the references thread and would say I am about 80% sure of how to do this, but don't want to make an expensive mistake so would appreciate some guidance. Thanks in advance.

 

[andy]

use 1.5T+E to wire the lighting circuit and to the switch. if there is a second swith, take a 3C+E (1.5mm) between the 2 switchs, so the first 1 should have a 3C+E and a T+E

do you know the permitted routes for the cables?

 

[AEM]

cables will be following old runs through ceiling voids and dropped vertically to switches. I read the buring cables doc in the references section and it wasn't clear to me whether vertical drops need to be buried 50mm or not, (the old cables were not), I will err on the side of caution unless I find out otherwise.

so 3-core between the 1 and 2-gang switches on ground floor, between 2-gang switch on ground to 3-gang sitch on 1st, and 3-core between switches on 1st and 2nd floors? (not really floors, house is on split levels).

So ground floor lighting circuit powers entire hallway over all floors. Is this acceptable/approved practice?

 

[mapj1]

Should be OK, if the total number of lamps on one lighting circuit is less than 10, otherwise split into 2 groups and run 2 separtate wires to the consumer unit - thay can always share a circuit breaker or fuse later.

 

[andy]

if the cables run directly up/down/left/right from an accessory (socket, switch etc) then they do not need to be protected (altho capping is a good idea).

if they run anywhere else, i.e diagnal from an accessory then it needs to be protected or buried at least 50mm (but by the time u get that deep, your under 50mm at the other side