where to position downlights

petedel · Nov 29, 2013

Im planning on removing two lighting points from my living room ceiling and replacing with 8 230v downlights (2rows of 4).

the room is 3.6m x 5.0m

In order to get the best use out of these would it be best to divide the ceiling into 8 imaginary sections an then use each centre as the new lighting point or divide the length by 5 and place at every metre and same for the width ( 3.6/3 so lights placed 1.2m apart?

ceiling/floor space is accessable from above and doesn't have any insulation inside

before anyone asks I have 2330 level 3 and 17th edition, I also have access to a metril mft that has a valid calibration certificate

MDJ · Dec 3, 2013

Dave 85 said:
Sorry dude but this is just plain wrong. This stuff is basic, it baffles me the number of electricians who cant do lighting plans.
To get the most even spread of light throughout the room you want:
(example)
wall-1.25m-light-2.5m-light-2.5m-light-2.5m-light-1.25m-wall
or
wall-0.6m-light-1.2m-light-0.6m-wall
etc etc
As for avoiding joists....it's an artform.
I mark the ideal positions, draw round the holesaw, spike the centre and 4 points round the edge on all lights to check for joists before cutting any holes. If one light needs to be moved I will generally attempt to move any others necessary to maintain even spacing. It can take time.

To get past joists, with no top access, I just notch 3" by 1" out of the plasterboard under each joist, clip the cable to the underside of the joist and then....
A. Tell them to call a plasterer
or
B. Wedge folded up down lighter instructions in the hole either side of the joist and slap some one strike filler over it. (I don't claim to be a good decorator)

The op had already metioned he wanted to fit 4 in a row in the room and asked for a guide in fitting them in hence the divide by 5 mentioned, it would not have been far off what you have mentioned

um no, that would be plain wrong, you need to ensure the fire rating of the ceiling is not compromised, what you just suggested is almost a DIYers method LMAO

Dave 85 · Dec 3, 2013

MDJ said:
The op had already metioned he wanted to fit 4 in a row in the room and asked for a guide in fitting them in hence the divide by 5 mentioned, it would not have been far off what you have mentioned

um no, that would be plain wrong, you need to ensure the fire rating of the ceiling is not compromised, what you just suggested is almost a DIYers method LMAO

Divide by the number of lights not the number of gaps. It makes more sense.
I use the instructions from fire rated down lights.....I assumed the instructions are fireproof too??
if not I shall be having a very serious word with JCC!

MDJ · Dec 4, 2013

Dave 85 said:
Divide by the number of lights not the number of gaps. It makes more sense.
I use the instructions from fire rated down lights.....I assumed the instructions are fireproof too??
if not I shall be having a very serious word with JCC!

But Dave to fit four lights in a room you divide by 5 M8, I do agree with your point earlier actually, TBH I normally add the first light in at around 600 ish from both ends then if I have to add 3 others in for example because that's what the customer has bought or wanted then it is a simple calculation to add the remainders in, anyhow who cares, I don't doubt we would both get the Job done one way or another.

uksparks · Dec 4, 2013

I was just going to say joist permitting, but beaten to it, the amount of downlighters I put in, i dream about them now! I'd always put a min of 8 in any room, I tend to go for 750mm apart but it really depends on what's in the way etc and how it needs to look. Bathrooms always put t least 9 due o the ip rating it makes them appear dimmer etc.

Octopus · Dec 4, 2013

uksparks said:
I was just going to say joist permitting, but beaten to it, the amount of downlighters I put in, i dream about them now! I'd always put a min of 8 in any room, I tend to go for 750mm apart but it really depends on what's in the way etc and how it needs to look. Bathrooms always put t least 9 due o the ip rating it makes them appear dimmer etc.

You must work in some big pads!