Loft insulation and electrical boxes/cables

[groovybug]

Hello everyone,

Just moved in our new (old) house. Checking the loft, I see that the previous owners use loose fill insulation over all the loft. My slight worry is this cover all the wiring and electrical junction boxes. The wiring up here is only for lighting, and all the light fixtures are LED bulb so will draw very little current and heat. Does this pose any fire risks? If so what do you recommend to do?

Many thanks

 

[JohnD]

is it white polystyrene blobs? Or is it granulated paper, or mineral wool?

expanded polystyrene must not be allowed to contact PVC cables as it makes them sticky and crack.

You can separate them with a cover, even brown paper will do.

 

[groovybug]

@JohnD Great question. Here is a photo. Could you tell what type of insulation it is? I guess it is mineral wool but not 100% sure. I remember there was a piece of plastic bag that said "Wickes Loose Lay Insulation", however I threw it away .

 

[JohnD]

it's fluffed up mineral wool. Not a problem.

As for insulation over cables, the lighting circuit is very lightly loaded, so no risk of overheating. If you have an immersion heater or an electric shower, the load is higher, and sometimes for long periods, so the cable should be either exposed to the air (e.g. on top of the joists); or in contact with an uninsulated surface, such as the ceiling below.

If you want to top up your insulation, I recommend the rolls of brown mineral wool treated with Ecose, which does not shed irritant dust or fibres. It is made by Knauf but widely sold as an own-brand in the sheds. "Ecose" will be marked on the wrappers.

I find the old yellow fibreglass very irritant.

 

[groovybug]

it's fluffed up mineral wool. Not a problem.

As for insulation over cables, the lighting circuit is very lightly loaded, so no risk of overheating. If you have an immersion heater or an electric shower, the load is higher, and sometimes for long periods, so the cable should be either exposed to the air (e.g. on top of the joists); or in contact with an uninsulated surface, such as the ceiling below.

If you want to top up your insulation, I recommend the rolls of brown mineral wool treated with Ecose, which does not shed irritant dust or fibres. It is made by Knauf but widely sold as an own-brand in the sheds. "Ecose" will be marked on the wrappers.

I find the old yellow fibreglass very irritant.

@JohnD Thank you, that's really good news. Is there any risk around the junction box at all? I was thinking getting a plastic box to cover the junction boxes in case there might be spark.

And you are absolutely right about irritant, I spent some time moving the wool around to locate the junction boxes and my arms and legs are very itchy, almost like being cut with tiny glass particles

 

[JohnD]

it won't hurt the junction box. Fibre is non-conductive and non-flammable

but of course keep the lid on so the inside is clean. You can add a cover if you want.

hosing off with COLD water should wash away the fibres from your skin. Clothes can rub them in. Then shower and wash your hair and clothes. Blow your nose.

 

[groovybug]

@JohnD Hi John, I'm looking to top up a layer of insulation and trying to find the Ecose type you mentioned but couldnt find any (I can see the it's mentioned on the Knauf website). Which store sells them or if you have an online link please let me know. Much appreciated.

 

[JohnD]

Example

B&Q
https://www.diy.com/departments/kna...on-roll-l-4-83m-w-1-14m-t-200mm/182147_BQ.prd
Enlarge the picture

Wickes
https://www.wickes.co.uk/Knauf-170mm-Standard-Top-Up-Loft-Roll-Insulation---6-47m2/p/109450