recessed lights, loft insulation and boards

[fatty]

Hi. I have recessed lights in the ceiling upstairs and wish to insulate and board out the loft for storage. The 50W halogen bulbs get quite hot and I'm wondering about the distance required between the light and any insulation (fibreglass) I install e.g. is a 10 cm radius sensible? Also, what about the vertical distance between the plasterbaord containing the light and the board I place in the loft? My joists are 100 mm, is that enough space?

Secondly, I notice the cabling used appears to be of the solid copper type (red, blue and earth) ~2.5 mm square. Is it ok to lay the insulation on top of this cable (I'm thinking about heat generated in the cable etc...)?

Thirdly, I notice that the recessed lights (six of them in the bedroom) are in a single line from the junction box i.e. the cable goes from the junction box to light 1 then from light 1 to light 2 etc... ending at light 6. Is this correct or should the cabling also go from light 6 back to the junction box to create a mini ring circuit?

Thanks for your help.

 

[RigidRaider]

1 - Yes, they do get hot. Mine are all well open to the attic with the glass wool cleared about 80mm away and I try to keep the transformers clear too. I have installed one under the loft flooring, also about 100mm, which I didn't consider enough so I got the jigsaw out and cut a 200mm hole which I plan to cover with a metal grid to stop anyone putting a foot down it.

As a side benefit, having them well open helps to light the attic with the spillage.

2 - Cable size, can't advise but mine use standard lighting cable to the trannies. You can't keep the cables from under the glass wool in the real world especially if you have added a layer.

3 - Mine were wired by a professional in the same way as yours. Out but not back.

 

[fatty]

Thanks for the comments. I've noticed that some rooms are wired differently from others. Some are wired as originally described (junction box - light 2 - light 2 - ... light 6) but two rooms appear to be wired in a mini-ring i.e. junction box - light 1 - light 2 - ... - light 6 - junction box. Does this second method have any significant advantage (or disadvantage)?

By the way, I like your idea of cutting holes in the boards for cooling. The only thing is, I was planning to put down some old carpet to try to make up for some of the insulation lost by compressing the fibreglass.

Any comments would be very welcome.

 

[fatty]

I don't mean to be rude, but does anyone have any further thoughts?

 

[Bowness72]

You can buy some sort of shroud to put over the lights which then allows you to put insulation around I believe, and I think these ones from screwfix let you do something like that although I do think I have seen other variations.

http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=102507&ts=59319&id=56254