Electrical prep before insulating and boarding attic

Lumen · 28-01-2017 12:05PM #1

This is my attic. It is inadequately insulated. I want to add 250mm or so of double-layer insulation and probably board over it using loft stilts.

Problem is, there's wires everywhere, connected to things like ceiling spots and dimmable transformer things, and once I cover them over with insulation and boards any future electrical maintenance will be hard. I want it to be easy.

What would an electrician do? Re-route them up the beams/walls?

Is this worthy of the WTF Electrical Photo thread?

PirateShampoo · 28-01-2017 12:08PM

Have you considered using foam insulation sprayed to the felt?

Lumen · 28-01-2017 12:13PM

PirateShampoo wrote: »

Have you considered using foam insulation sprayed to the felt?

You mean insulating the ceiling rather than the floor of the attic?

edit: right now it's 20C upstairs, 10-13C in the attic, and 0C outside.

exaisle · 28-01-2017 12:15PM

You could consider changing to mains led ceiling spots which removes the necessity to access transformers..
Also, I'd be far more inclined to insulate the roof and floor the attic normally. Stilts seriously restrict the amount of usable space and flooring the attic will aid the insulation already in place..

A Law · 28-01-2017 12:17PM

exaisle wrote: »

You could consider changing to mains led ceiling spots which removes the necessity to access transformers..
Also, I'd be far more inclined to insulate the roof and floor the attic normally. Stilts seriously restrict the amount of usable space and flooring the attic will aid the insulation already in place..

I've done this and after reading a few different articles I found the best thing was to insulate the floor between the joists, perpendicular to the insulation already down. You're trying to keep the heat in the house, not in the attic.

exaisle · 28-01-2017 12:27PM

I think the important point is that the OP wants to floor the attic also.

Lumen · 28-01-2017 12:35PM

exaisle wrote: »

I think the important point is that the OP wants to floor the attic also.

Yes, but I guess I don't necessarily need to floor it since I have storage elsewhere.

I suppose the reason I'm asking in the electrical forum is because

(a) I don't know whether what I have right now is appropriate/best practice in terms of organising wiring in an attic space.

(b) I want to make future wiring maintenance easier.

I understand that insulating the rafters will make the space generally more flexible to use, but it would obviously be more expensive and if done wrong could trap moisture and cause the rafters to rot.

A Law · 28-01-2017 01:06PM

http://touch.boards.ie/thread/2057354829/1

Stoner · 28-01-2017 01:46PM

If it was me I'd tidy up the cabling. It might require some rewiring. There is a delimiting factor on the current carrying capacity of cables when you insulate over them.

However, you've a job to do.

Usually in an attic the cables for an electric shower are the ones most likely to be affected, any cable carrying a large load, like the immersion or possibly a lighting circuit with a lot of fitting or external halogen fittings on it.

So changing out the traffos to GU10 230V led fittings will drop the load on your lighting cctv, as will changing external lighting to LEDs.

But there's nothing to delimit the current on your shower cable and this would be better above the insulation. In my house all the cables are under the insulation, everything is wired in straight lines coming off a centre spine.

The cabling in your attic looks like many installations, there is nothing unusual about it looking at it quickly.

If you get a sparks to tidy up the cabling, you could get all that insulation out of their way , get rid of the transformers, measure the diameter of the holes your spots have and order enclosed fire rated fittings that have the insulation cage/barrier on them so that you can pull the insulation around them and you won't have cold air coming in through the holes.

The tidy cables will all be below the tops of the timber so that you could floor it if you wanted
Note the main areas where cables are, photograph it

Have the shower cable long enough so that you can have it outside the insulation of you want.

You are good to go then, hoover the attic space ( you'll be amazed at a how fast you'll do it and B how much potentially flammable dirt is there.

I'd reuse all the insulation you have. You can then get king span insulation backed ply to floor the place and insulate it in one hit

I think you'll notice a big difference by just dealing with the spot lights as I suggested.

Lumen · 28-01-2017 03:53PM

Thanks Stoner, that's brilliant.

I'm getting some quotes for insulating the rafters then I'll sort out the wiring and lights as you've described.

28-01-2017 07:43PM

PirateShampoo wrote: »

Have you considered using foam insulation sprayed to the felt?

Rather than insulate the ceiling? I think that is a bad idea. This will mean that heat from below will pass through to the attic. Result: Warm attic and cold below. I would rather insulate the ceiling with a view to retain heat in the habitable areas. In terms of the wiring I think that Stoner hit the nail no the head.

Stravos Murphy · 28-01-2017 09:44PM

Stoner wrote: »

If you get a sparks to tidy up the cabling, you could get all that insulation out of their way , get rid of the transformers, measure the diameter of the holes your spots have and order enclosed fire rated fittings that have the insulation cage/barrier on them so that you can pull the insulation around them and you won't have cold air coming in through the holes.

I think you'll notice a big difference by just dealing with the spot lights as I suggested.

You are misunderstanding what a fire rated down lighter, you are creating a fire hazard by suggesting the above.
A fire rated downlighter contains a fire from the floor below it. If you want to be covering and insulating down lighter fittings get ic ones. These are fraught proof also.

Lumen · 28-01-2017 10:03PM

Stravos Murphy wrote: »

If you want to be covering and insulating down lighter fittings get ic ones. These are fraught proof also.

Like this?

https://www.downlights.co.uk/downlights/aurora-insulation-covered-downlights.html

Stravos Murphy · 28-01-2017 10:18PM

Yea they are the ones, I have used them type the Aurora stuff is good.

Stoner · 29-01-2017 03:20AM

Stravos Murphy wrote:

You are misunderstanding what a fire rated down lighter, you are creating a fire hazard by suggesting the above. A fire rated downlighter contains a fire from the floor below it. If you want to be covering and insulating down lighter fittings get ic ones. These are fraught proof also.

I know what a fire rated down lighter is, I suggested that the OP get fire rated downlighters with the insulation cage on them, that's two things

"These covers attach to the top of a selected fire rated downlights in order to make it coverable by insulation material in a ceiling void. Converts the fitting into IC Rated"

The above is quoted from the Aurora light fitting website

http://gb.auroralighting.com/Lighting-Products/Indoor-Luminaires/Fire-Rated-Downlighting/GU10-Fire-Rated-Downlights/GU10-Fire-Rated-Accessories/70mm-Fire-Rated-Downlight-Insulation-Cover.aspx

I've recommended the Aurora fittings here many times over the past 4 or 5 years, you mentioned them yourself on this thread.

I think you just didn't understand the post TBH, I mean that in a genuine way as you then recommend a fitting I would agree with for this application. I've reread my post and I don't think it needs to be altered, but I could be wrong.

Can you do the same please with your post, mainly the section where you say the advice creates a fire hazard, thank you.

geo88 · 14-09-2018 09:06PM

Apologies for reviving an old thread, however my question is quite similar.

My attic looks similar (messy cables) and I'd like to add extra insulation and floor parts of it. I have no transformers/spot lights (and never intend to add such), however, I am looking at doing a rewire down the line (in about 3-5 years).

How does the advice change in this case?
Would adding extra insulation and flooring result in more expensive quotes for the rewire? Should I just add insulation and not floor the attic?

Given the pending rewire - should I just keep the cabling as is? (uPVC cables, no rubber wiring as far as I can tell).

@Stoner - any thoughts on this?

Electrical prep before insulating and boarding attic

Comments