Laying a cable in the ceiling

[jonnyraine]

This is my first proper DIY job with electrics. I'm running a cable from a light to a ceiling fan, which isn't all that far away (about 50cm). I know how the electrics work, as in which cables to connect to which, but it's physically laying the cables that I'm not sure about.

The room is a ground floor flat roof extension so I can't just go into the room above and pull up floorboards to run the cable, so how do i do it? Do I pull up the felt roof at risk of damaging it? Am I able to chisel/drill through the ceiling and plaster it up after me? Or is there a standard technique for this?

 

[electronicsuk]

If you take up the felt above then you will probably do yourself thousands of pounds of damage, as the roof is bound to leak in the next heavy rain. That's not to mention that there will be a sheet of thick ply underneath the felt that you'd also have to cut through and replace.

Standard practice in this situation is to remove the ceiling plaster where necessary, drill through joists, run the cable(s) and then make good afterwards. It might have been easier to buy a ceiling fan with built in light fitting, but that's your choice.

 

[Richard C]

This is my first proper DIY job with electrics. I'm running a cable from a light to a ceiling fan, which isn't all that far away (about 50cm).

How to do: get yourself a hole cutter set & use the one that will make a hole large enough for you to get your hand through. Cut strategically placed holes in the ceiling so you can feed the cable through to where you want but save the circular bits you cut out. If the cable is running across the joists you will obviously need to cut a hole right next to it so you get the drill cutter into the ceiling & drill through the joist. When your finished stick the circular bits back into the ceiling with a trade grab adhesive, stick some reinforcing tape around the join & plaster skim or fill over; if you do it right no one will ever see it.

Ceiling fan huh! If it's in a utility or other room then fine but if it's in a bathroom or kitchen; but before you start, just be aware of the regulations regarding DIY electrical work in these areas & the possible consequences of ignoring them!

 

[jonnyraine]

Did I really say ceiling fan...I meant extractor fan! I was in the middle of ready a study book when I wrote that...pah! Thanks for all your help

 

[Richard C]

Did I really say ceiling fan...I meant extractor fan! I was in the middle of ready a study book when I wrote that...pah! Thanks for all your help

You post is titled laying cables in the ceiling FFS, what a total waste of time! What subject is your study book then, how to be a total p**t or are you just taking the ****! Anyway it doesn’t really matter if the fan is in the ceiling or the bloody wall, the regs are still the same if that's your problem!

 

[jonnyraine]

hey you, richard c man. i wasn't mickey taking nor was the advice you have given me a waste of time. i still have to run a cable across the ceiling so the advice you've given me is most helpful, that is until you got angry. i've got to run a cable from the light across to the end of the ceiling and then down the wall, so now i know what to do so thanks...thanks a lot!

 

[electronicsuk]

Hmm, no idea why Richard went off on one, but he certainly gave the profanity filter a good seeing too.

Anyway, if you're installing an extractor and don't have proper access to the ceiling void, what exactly was your plan for venting the fan out of the building? Are you installing a vent through the felt roof directly above the fan?

 

[Richard C]

hey you, richard c man. i wasn't mickey taking nor was the advice you have given me a waste of time. i still have to run a cable across the ceiling so the advice you've given me is most helpful, that is until you got angry. i've got to run a cable from the light across to the end of the ceiling and then down the wall, so now i know what to do so thanks...thanks a lot!

Had a "bad hair" day yesterday; people continually messing me about, miss-understood & thought you were another one; sorry about that.

 

[jonnyraine]

no worries richard c! we all get like it from time to time! all is forgiven.

Anyway, if you're installing an extractor and don't have proper access to the ceiling void, what exactly was your plan for venting the fan out of the building? Are you installing a vent through the felt roof directly above the fan?

mr. electronicsuk, i'm installing the extractor fan (got it right that time!) in an external wall. so i need to run the cable from the light in the centre of the room across the ceiling to the edge where the wall beginbs and a couple of inches down the wall to the fan, right?

 

[ban-all-sheds]

Do you have a choice of external walls? If you do, pick the one at right angles to the joists..

 

[Richard C]

Run the cables from the ceiling down the wall into a triple pole fan isolator switch, preferably fused but not essential. Assuming your wiring the fan on/off with the light; if it has a timer, you will need a permanent live (4 core cable). You can position the switch high up if it’s just for isolation (I usually put it next to the fan) but if you intend to use it as an override, obviously you will have to mount it lower down. Cable from the switch on to the fan unit, observing the “safe zone” positions for cabling.