Wires in insulation

[an203888]

What is standard proactive for fitting wires in the insulation of a vaulted ceiling or flat roof for that matter. So when you have 100+ of celotex between rafters and then 50mm below then plasterboard. Where do you stick your lighting wires and then if you have some fire rated downlights do you simply cut a hole in the insulation to be able to fit them in?

Thanks in advance

 

[EFLImpudence]

What is standard proactive for fitting wires in the insulation of a vaulted ceiling or flat roof for that matter. So when you have 100+ of celotex between rafters and then 50mm below then plasterboard. Where do you stick your lighting wires

Fit between plasterboard and insulation. It will not affect 1mm² twin and earth on a 6A circuit.
You should have run the cables before fitting the plasterboard.

and then if you have some fire rated downlights do you simply cut a hole in the insulation to be able to fit them in?

No.
Get some surface mounted or very low-profile lights.
You do not need fire-rated lights in the ceiling.

 

[an203888]

Fit between plasterboard and insulation. It will not affect 1mm² twin and earth on a 6A circuit.
You should have run the cables before fitting the plasterboard.


No.
Get some surface mounted or very low-profile lights.
You do not need fire-rated lights in the ceiling.

So do I just cut a small groove in the insulation to put wires between plasterboard and celotex?

With regards to the lights, do you have any examples? Don't really want surface mount unless they are very slim. The slimmest built in ones I have found still need a 75mm depth behind the plasterboard?

 

[JohnW2]

With regards to the lights, do you have any examples? Don't really want surface mount unless they are very slim.

What do you count as 'very slim'? 20mm 'thick' LED ones are common (just Google!).

The slimmest built in ones I have found still need a 75mm depth behind the plasterboard?

That's why they're really not desirable/suitable for the sort of situation you describe. However, if you Google for "thin LED downlights", you'll find plenty with depths in the range 25-30 mm.

Kind Regards, John

 

[Taylortwocities]

o when you have 100+ of celotex between rafters and then 50mm below then plasterboard.

He has plenty of depth for most downlights without carving the Celotex. Unless I misunderstand he has 50mm free space plus 12.5mm plasterboard plus about 3mm for plaster.

 

[an203888]

He has plenty of depth for most downlights without carving the Celotex. Unless I misunderstand he has 50mm free space plus 12.5mm plasterboard plus about 3mm for plaster.

No - 100m of celotex between rafters, 50mm of celotex below rafters and then plasterboard. I'm thinking that adding a 75mm void between celotex and plasterboard is required. 50mm would be preferred but can't even find downlights to go into this space. Phillips do one which only needs a 60m void. However most of these voids seem to be for ventilation purposes, if not the led life might be shortened. I'm thinking that because there will be a full void then reducing the void depth shouldn't be a problem.