Loft insulation

beachBOYken · 2025-01-09T09:39:55+0000

Hi

Im wondering how often loft insulation should be replaced, I noticed the insulation between the loft floor joists is very dark looking in areas, its not been replaced in a very long time, maybe 20+years, only some parts got replaced when we installed some floor boards in the loft and that was quite a while back, so some parts look more new looking and gold in colour.

On that note I would prefer to do it myself, can anyone recommend a decent insulation I can fit myself, I think its pretty easy from what I remember, although the stuff we used last time made me itchy!

Hagar · 2025-01-09T10:03:50+0000

As long as the dark colour is due to oxidation, dust and maybe a bit if dirt it will not affect its performance. Dampness will.

The time to add insulation is in the warmer months when costs may be lower, wear a mask and goggles and wash or shower well when finished for the day.

SpellowHouse · 2025-01-09T10:17:46+0000

Mostly dark insulation is just caused by muck blowing in from the outside. If you are close to a road then this can be significantly more than if you are in the country. Anyway, it doesn't affect it's performance. What's more important is it's thickness. If you are saying it's old then it probably isn't thick enough. And in all cases it's better not to replace it, but to add to it. Most older houses have four inches of loft insulation. What I typically do is make a raised walkway, then build that up with another eight inches. Don't forget that as you increase insulation you should also add more to any pipes and tanks you have up there. A good rule of thumb is the same amount on tanks as on the floor and put as much as you can on pipes, since these are the things most likely to freeze in British winters.

Nikumba · 2025-01-09T10:20:37+0000

If you do it yourself, make sure covered up, any exposed skin rub talc on it, as this blocks the insulation getting into your skin and itching.

SpellowHouse · 2025-01-09T10:24:14+0000

Nikumba said:
If you do it yourself, make sure covered up, any exposed skin rub talc on it, as this blocks the insulation getting into your skin and itching.

That's very true. Seal your clothes with tape. Wear mask, gloves, googles and so on. And this weather is good for doing this, because you get very hot doing this work.

beachBOYken · 2025-01-09T12:44:43+0000

SpellowHouse said:
Mostly dark insulation is just caused by muck blowing in from the outside. If you are close to a road then this can be significantly more than if you are in the country. Anyway, it doesn't affect it's performance. What's more important is it's thickness. If you are saying it's old then it probably isn't thick enough. And in all cases it's better not to replace it, but to add to it. Most older houses have four inches of loft insulation. What I typically do is make a raised walkway, then build that up with another eight inches. Don't forget that as you increase insulation you should also add more to any pipes and tanks you have up there. A good rule of thumb is the same amount on tanks as on the floor and put as much as you can on pipes, since these are the things most likely to freeze in British winters.

I will have to check, as only glanced over at it when I was up there the other day, I think it needs removing and redoing, its quite poorly installed in some places, and not very thick in other parts. It could be damp as well, as one of our walls gets damp in the corners in the winter. Trying to work out what's causing that!

I have no pipes up there anymore, just wires from aerial and some lighting.

I know not to bury wires under insulation, is it ok to lay them on top?