12v down lights and loft insulation

[namnot]

Hi,

I’m in the process of doing a loft conversion with a roofer. I want to install a number of down lights. Does any one know how insulation you should cut out for the down lighters, they all going to be MR16 fire rates ones. The thing is the electrician on the jop want to leave 300mm x 300mm gaps for each light. These numbers of gasp will loss a lot of insulation and heat and cause a cold bridge.

I feel you can cut the holes the size of the down lights themselves and push them up through the whole would work better.

Will this work OK.

 

[Deluks]

Two methods are often punted about. Either use terracotta flower pots on top of the lights, or make up small plasterboard boxes to hold back the insulation from around the area of the light. Not giving the heat somewhere to go will just cause premature bulb/transformer failure and could be a fire risk. I wouldn't go with 300mm square, more like 150-200mm square, and whatever you use should be higher than the depth of insulation itself. So if you have 250mm of insulation then a plasterboard box for example should be at least that in depth.

 

[namnot]

Hi,

Thanks for the reply,most helpful.

I've now noticed that screw fix sell a fire rated guard 220 x 220 x 140mm which would work, might be a bit expensive but a thought.

Cheers

 

[Deluks]

You could make about ten homemade ones, out of a plasterboard sheet and a few bits of batten for the same price.

 

[SingingDwarf]

I've been researching options myself, as I'm getting my 1" of loft insulation topped up to the recommended 250mm under the Energy Efficiency scheme.

I've found this product and this product by Aurora, which claims you can lay loft insulation over the top in a continuous sheet.

Whats the general consensus here - you wouldn't touch it?

PS This would be for 240v halogen lamps, not 12V downlighters in my case.

 

[namnot]

I've noticed those products and I'm sure there be fine. However as I'm putting in a number of lights I've up some some plasterboard boxes (a lot cheaper). I'm also using MR16 (fire rated) 12v lights, wouldn't touch the mains ones myself.

 

[shuttlex]

hi so with the plasterboard box thing does this have to be vented or can you lay the insulation on top?