Pitched roof spotlight conundrum

[Super_Paulie]

afternoon everyone.

My vented pitched roof on the rear extension was built to the architects plan, and its pretty standard stuff for a cold roof, see the attached drawing.

 

Im at the plasterboarding stage now and the missus has decided she now wants downlights/spots instead of the original plan of surface mounted directional lights.

 

Obviously i dont have the space to sink these lights now, so im looking at my best options. Would using an insulated plasterboard rather than the single 12mm layer work to give me the required depth? Im not sure on the insulated board, service void, then more insulation buildup. Seems thats not right. To add a spanner to the mixer she wants them to be RGB or similar to change the colours of that whole section of the house. Id imagine a GU10 bulb would have a minimum required depth of around 100mm which seems impossible to accommodate currently.

 

Im aware on the warm roof/cold roof etc etc, but it is what it is and thats what I have. So any suggestions that may help id really appreciate it. As I am over the regs with my 150mm insulation i could in theory create a 20mm void in that second layer if required and still be within tolerance of the required 130mm. Would a divorce be the easiest option?

[Temp]

There are some adjustable LED downlights designed for small voids but you will have to search and check the void depth required. The specified void depth normally includes the plasterboard layer but check. Just one example Google found.. 

 

https://www.nationallighting.co.uk/nitropro-tri-wattage-360-recessed-fire-rated-4cct-8w-led-downlight-dimmable-ip44-matt-white?vat=1&gad_source=1&gclid=EAIaIQobChMI-I2y5sDghwMVJZdQBh0AIwcCEAQYAiABEgIHK_D_BwE

 

Min void for that one is 45mm so would need 33mm battens and 12mm plasterboard.  

 

Get RGB colour controllable will be harder but..

 

https://www.lightingstyles.co.uk/adjustable-cct-fire-rated-led-downlight---bathroom-suitable

 

but colour not fully adjustable. Just cool to warm. again 45mm void.

 

If already battened can you add another layer of battens? 

 

Edited August 6, 2024 by Temp

[Temp]

One option might be perimeter lighting using LED strips pointing up towards the opposite ceiling pitch. Make the whole ceiling glow.

 

[Super_Paulie]

seems like chinese crap, but i guess a solution exists.

 

https://www.amazon.co.uk/ALUSSO-LIGHTING-Downlights-Spotlights-Compatible/dp/B0CLV1VQBW

[Temp]

On 06/08/2024 at 16:17, Super_Paulie said:

seems like chinese crap, but i guess a solution exists.

 

https://www.amazon.co.uk/ALUSSO-LIGHTING-Downlights-Spotlights-Compatible/dp/B0CLV1VQBW

 

They don't appear to be adjustable so wont point downwards so there would be a lot of glare.

[Andehh]

Hanging lights on very short pendants? Go for black or something contrasting... Match kitchen handles etc?

 

Down lights are over rated....

 

 

Also be careful of reflecting light off your plasterboard, any imperfections in the plasterboard, taping or plastering will be shown up!

[Adsibob]

Personally, I would just tell the wife no. Seems silly to go to all this trouble just to fit recessed downlights. Lots of other options exist that won’t ruin your insulation.

[Super_Paulie]

On 06/08/2024 at 14:59, Temp said:

If already battened can you add another layer of battens? 

 

 

That's what I've ended up doing, doubling up the battens to give me 50mm + plasterboard so a void of 65mm give or take.

 

Should I be insulating, acoustically between the battens? I don't want to debate the lighting cables so the insulation would only be between say every other batten gap where there are none. Might make it pointless?

[Temp]

Shouldn't need to worry about derating wires as the current with LED is pretty low.

[Super_Paulie]

Yeah probably. But the LEDs have drivers in the void as well and I guess I wouldn't want to cover those in insulation. I could insulate within the void but leave full sections (with the lights and drivers in) empty, but I'm not sure gaps like this just make the whole venture pointless?

[JohnMo]

LED downlights come with a transformer that requires just about 50mm gap. So you need to form 50mm service gap. LED lights need plenty of cooling otherwise they fail quite quickly otherwise, so insulated plasterboard may not be a good solution.

 

Once built how are you going to maintain the lights without scaffolding?

 

We moved away from ceiling lights in our lounge (45 Deg ceilings) because they would be so high, you could not get at them easily. Plus they are so far you you they are cr*p.

 

Instead we did combined up and down lights on the wall. But we generally just use side lights only now.

[JohnMo]

15 hours ago, Super_Paulie said:

Should I be insulating, acoustically between the battens

No

1 minute ago, JohnMo said:

LED lights need plenty of cooling otherwise they fail quite quickly

 

[Super_Paulie]

1 hour ago, JohnMo said:

LED downlights come with a transformer that requires just about 50mm gap. So you need to form 50mm service gap. LED lights need plenty of cooling otherwise they fail quite quickly otherwise, so insulated plasterboard may not be a good solution.

 

Once built how are you going to maintain the lights without scaffolding?

 

We moved away from ceiling lights in our lounge (45 Deg ceilings) because they would be so high, you could not get at them easily. Plus they are so far you you they are cr*p.

 

Instead we did combined up and down lights on the wall. But we generally just use side lights only now.

my house isnt as grand as most on here, the roof is basically a mono-pitch on the back of the house which goes from maybe 2.6m above the doors up to 3m, over 2m something like that. Its easily reachable with a ladder. Also i have a 50mm gap as i doubled up the battens now, seemed the easiest option. The drivers are 25mm and the LEDS themselves are 30mm so with a 50mm gap behind the 12.5mm plasterboard i'll see how i go.