To go central lighting or nnot - thats the question?

[TumbleDNA]

Hi everyone - firstly a happy, and hopefully prosperous new year to all.
I thought I would start the year on a thread that that’s been around before but usually leads to more questions than answers - central (and maybe in future) smart lighting.
I have a new build to rewire which is a big building and because of this made me have a rethink about how I wire it. There's a couple of issues driving this which others will no doubt have faced before already:-
- the shape of the building means a lot of cabling to a CU at the other end of the building;
- the customer wants a lot of light fittings / led strip / and downlighters to be installed - again a lot of cable and switching;
- the attic is going to get 450mm of rockwool and I just hate throwing cable in and burying it all under it. Going back up after is near impossible as you can’t find the timber to walk on when it’s under that amount of insulation;
So: my options I think are:
- run all of the attic wiring in tray or something higher above where the insulation will be laid - problem here is that I will end up with a cobweb of cables dropping down through the insulation to each light point / switch etc.
- run all cables first but go for a central wiring panel solution. Insulation can then go over them but all cable ends are available at either end so risk of wiring errors / ability to make changes is mostly covered. The downside here is more cabling though;
Any thoughts guys - there's clearly not a perfect answer but i'd value others expereicnes on this

 

[telectrix]

first use a font size that we can see

 

[TumbleDNA]

first use a font size that we can see

Sorry all, and thanks telectrix - I wrote it out on word in a different font size!!

 

[Rpa07]

100x50 or 50x50 trunking with run offs. Gives more breathing room and no grouping issues.

 

[Midwest]

Run all the lighting cables first, before they lay the itchy stuff. JB's if applicable, mounted above insulation.

 

[TumbleDNA]

Thats what i'm thinking at this stage but was also wondering if anyone has gone further and kept all of the cabling up on baskets or something - makes maintenance / changes easier but then climbing around afterward on 450mm of rockwool isn't easy either

 

[plugsandsparks]

Depending how big is big, i have used 6 inch tray, in some areas 2X6 inch tray. Then for all the drivers i have used large plastic boxes to house the drivers and the like. Central lighting panel located in a cupboard.

 

[Wilko]

There was "one million" layers of insulation on a recent job and they'd done a nice job installing it. I was literally swimming in it to find existing cables and jb. Ssooo much fun ... So if you can get the cables up on a tray you'll be on my Christmas card list .

 

[TumbleDNA]

Just called at the job today and noticed about 50+ rolls of rockwool had been delivered!! - Kind of helped make my mind up about using Pemsa basket fixed to the roof trusses _ can then at least add something if needed. Still havent decided on central wiring cabinet in cupboard through Plugsandsparks - sounds like its the answer but keen to know if others have gone / are going this route

 

[123]

I assume you haven't given a quote for this job and are just on day rate?

 

[TumbleDNA]

Agreed a basic price but I explained that this would depend on attic conditions and any changes the client wanted. There's a lot of LED strip now appearing in the spec which is making me this a central wiring panel on each floor may make the lighting easier

 

[pirate]

Just finishing off a job installng ceiling heater panels which come with fitted plugs. The flexes have to run under 300mm of insulation topped off with t&G flooring.
We've installed 68mm plastic downpipe conduits, so if needed the flexes with their plugs on can be pulled back. Leaves a nice airgap too!

 

[plugsandsparks]

I would check what type of dimming controllers you intend to use and work out how much space you are going to need. I am using dali and KNX for control but generally if you are using RGBW, that can use 4 channels just for one strip of LED tape. Dali is a doddle as its 5 core daisy chained cable which can do a huge distance. Ditto KNX. BUt i was always worried about what extra stuff the client was going to add which affects space in a cabinet. With Dali you can run just a single cable for upstairs and another for downstairs, all switches are a separate daisy chained cable KNX, Cat5, that type of thing or you could use wireless. So into the cabinet you can just use 4 cables in total for the whole lot. If you are going to run one cable per zone into the cabinet you could end up with a very large number....