halogen downlights & fire guards

[Hack]

I have a downstairs bathroom extension with halogen downlights fitted by the previous owner.
There is a lot of heat lost out/ cold air let in through the roof cavity and I want to lay more insulation so I've bought some fireguards from screwfix:

http://www.screwfix.com/prods/97932...ire-Hoods/Halolite-Downlight-Fire-Guard-220mm

and these fit fine over most of the downlights and I can lay more insulation over the top.

The problem is that the specs state that the luminiere needs to be 50mm from the fireguard presumably to lessen the risk of a short but one of the fittings is close to the joist. The aperture is 70mm so this puts the middle if the luminiere 35mm from the joist and thus 35mm from one side of the guard.

Is this going to be ok or should I consider cutting down the guard so I can get it more central over the luminiere and fix it to the joist?

Thanks

 

[Taylortwocities]

It won't short over 35mm, you'd need thousands of volts for that to happen.
The distance is probably to prevent the joist being charred.

 

[Hack]

ok thanks, should be ok then but just to be clear, the luminiere will be approx 35mm from the metal side of the fireguard

 

[mointainwalker]

You may have solved your electrical question, but you haven't solved your building one.

All that hot air will be carrying lots of moisture into the loft/insulation.

The inevitable result is condensation.

If you have condensation in fibre-wool, the water reduces the insulating effect enormously ( 80 % ? ). If you have board insulation and the moist air gets round it, you risk (long-term this is ) damage to structure and moisture damage to anything stored up there.

Solution is to install a moisture-barrier ( plastic-sheet) between ceiling and insulation to prevent moist air getting on cold side of insulation where it can condense.

 

[Hack]

thanks but there's not much hot air down there so shouldn't need to worry. The room was originally a bathroom but I moved the bath/ shower upstairs so now it's just a (at the moment very cold!) utility room with a washing machine and wc.
thanks

 

[Taylortwocities]

The air downstairs will be warmer than the air above the ceiling. As the warmer air is drawn into the cooler space it will condense and form drops of moisture.

Try it, breathe on a cold window sometime.


This moisture in the roof space will, over time, rot the roof timbers.

 

[Hack]

I think I probably didn't give enough information in the original question first time round but suffice to say condesation won't be an issue.
Thanks for the advice