Truly Biodegradable Lagging for Plumbing?

Hello!
I'm hoping this community can help point me to some alternative options for genuinely biodegradable pipe lagging.

We recently moved all our plumbing up into our attic (long story) and now need to lag it. I've been intent from the start on lagging with something biodegradable because mice in the attic will inevitably get at it, and I hate the amount of toxic debris already strewn through the space because of this. I don't want to add more, or to know I'm sending that stuff out into the surrounding nature.

The problem is, when I search for products I find many advertising "100% wool pipe wrap" etc., but it seems these claims are usually misleading. We bought one well known brand (UK) and found the wool is felted against a more polyester-type backing. The company hides this info on a completely unrelated page of their website. Whatever I search, I get noise from all the greenwashing. OR the product is prohibitively expensive.

Can anyone suggest something that's truly a biodegradable product suitable for this purpose? We have limited budget to spend on it, because we'll need to buy it in bulk and/or build it up over time. We also wondered about reusing, e.g., eco wool packaging used for frozen goods, but not sure exactly what's in that, how treated, or how it might react to fire given it's not the intended purpose.

Any advice or suggestions for things we might consider would be much appreciated. - Thank you 🙂

The value of raw wool has plummeted. Twenty years ago in Wales it cost a pound a head to shear, then we'd get a pound per fleece. Now, in Portugal, if you're prepared to take a whole giant builder's bag full, you can pick it up for the cost of going to fetch it. I managed to scrounge a smallish bag off a friend who'd taken too much for an insulation job and made myself a new pillow which I'm enjoying. I bet the situation s similar in Scotland now. Can you find any sheep farmers and ask if they have any bags lurking in a barn?

Thanks so much. I would totally try to do that if it's a viable option. Any idea how home insurers tend to view use of raw materials for these sorts of purposes? I.e. if we were unlucky enough that our house burned down, might the insurers claim it was worsened by use of "off-label" materials because it wasn't a product purchased for the purpose? We all know in a community like this that wool isn't more flammable than the next thing, but I do worry about systemic prejudice against using stuff like that.

As an aside, back when I lived in Wales, not far off 20 years ago, I knew farmers who were burying sheared wool in the ditches cos it cost them to get rid of it otherwise. I used to pick up loads of pretty decent stuff for free to do natural dyeing. So sad.

Wool is flame retardant by nature. It's far less flammable than plastics. Adding borax also helps with fire safety and discourages pests.

I second the idea of using sheep fleece - ask around. The farmers here were burying the fleece because it was costing them to 'sell' it. I would just wash it to get rid of the worst of the dirt, wrap it round the  pipes and wind jute or cotton string round to hold it (or wool!). As Phil says, wool is naturally fire retardant see This info from wool insulation Wales for example. I don't think you need borax - that is used to help against insect damage though.

You can buy wool pipe lagging made for the purpose : https://chimneysheep.co.uk/products/wool-pipe-lagging for example. It doesn't seem that expensive to me (£9 to cover about 3m of pipe), so you might just want to splash out if you don't find an easy source of wool locally.

I had to look up lagging it's not a term I knew.
I think we would just call it pipe insulation around here.
There are aluminum products made to protect that insulation from mechanical damage.
Diy, you could just use aluminum flashing.

Another kind of protection, wrap it in stucco.

Thanks all. Discussed with partner last night and have reassured ourselves that it should be a fight for any insurer to claim a fire was worsened by raw sheep fleece given all the other rubbish most attics generally contain, so I plan to ask around locally and see if I can find a farmer with some to offload.

In terms of holding it in place, I'll be using some sort of metal mesh to protect both the wool and the pipes from mice. Due to cost issues (this was not a major CH overhaul we ever planned or budgeted for) we were forced to use plastic pipes, so we have an added vulnerability to teeth to consider.

Nancy Reading wrote:You can buy wool pipe lagging made for the purpose : https://chimneysheep.co.uk/products/wool-pipe-lagging for example. It doesn't seem that expensive to me (£9 to cover about 3m of pipe), so you might just want to splash out if you don't find an easy source of wool locally.

This is easily one of the best ones I've looked at and would be my preference. But when you consider the overlap needed and that we have probably over 30m of double pipes to wrap, £9/roll will add up, especially on top of the mesh we'll need to buy, and all the pipes, joints, valves etc. we already bought (i.e. the unbudgeted splashing out has been ongoing for months). Neither of us has a secure long-term income, so we have to be careful. Potentially free sheep fleece sounds AMAZING by comparison - I was just so worried it might be considered unapproved for insurance purposes.

William Bronson wrote: There are aluminum products made to protect that insulation from mechanical damage.
Diy, you could just use aluminum flashing. Another kind of protection, wrap it in stucco.

Some sort of foil is definitely worth a thought - thanks. Especially in the trickier sections as it might be a bit mouldable. I'll look into that. By stucco do you mean literal walling? Like encase the pipes in plaster? Not sure our ceilings would withstand that if so (nor my impatience to get the job done quickly). Foil sounds like something to explore though, and then I was also looking at knitted meshes like this: https://themeshcompany.com/copper-rodent-mesh-a-tried-and-tested-solution-to-keep-rats-mice-away/, but cheaper non-copper ones hopefully. I think that stuff could work quite well to contain unshaped fleece.

Luckily I still have a decent pair of carders from my spinning and natural dyeing days, so we have the basics for a little wool processing production line. Just wondering how much a fleece might actually need washing. On the one hand, lanolin = a bit more durable and insulating, so it might be counter-productive to wash too much out. On the other, the attic would absolutely reek on a rainy day, but maybe not in a bad way? I DO like living close to animals, my partner less so I think.  Also, would a cosy sheepy smell attract or deter mice? Oh and moths! - maybe that was what the borax suggestion was for (thanks Phil Stevens) - I didn't make the connection till now (should, cos already have moths in everything), but YES, definitely worth considering.  ....SO many more questions now.

Aluminum flashing is not foil - that is a distinctly thinner product and would not be likely to stop rodents for long. Flashing is used in house construction for weather-tightening to safely shed water or keep moisture away from wood.

I mean stucco as in wrapping something in a metal mesh and pressing a cementous material through the mesh, to form a hard shell.
One could also call it ferrocement, though  I think that is is reserved for free standing structure, not a outer coating.

In any case, I have built a kitchen sink counter that is made wood, stapled on window screen, and cement (it might have had some sand in it).
It has remained solid and waterproof for years.
Your application should not see any moisture anyway.
I suspect cement would stick directly to wool, or felted wool.



For almost no money, you could use aluminum cans.
You would need ,at most one can for every very 4-5 I h stretch of pipe.
While aluminum foil wouldn't protect the lagging, the metal of an aluminum can should.