Raw wool insulation

Hi there.

I have a straw bale workshop almost compete and I had intended to insulate the roof with raw wool treated to stop moth infestation.  I have now been told the treatment I was going to use is no good (borax substitute) and that the one I should use (borax) is only able to be applied by a professional.

I have access to lots of raw wool so it makes lots of sense to use rather than spend a fortune on commercially available wool insulation.

Anyone have any experience with raw wool insulation . . . ?

I’m in Northern Ireland.

Any advice gratefully received

John

What is the borax substitute they are using?

Borax is a biocide and has been causing health issues with overuse (some kids toys like slime use borax).  

That said, most people add it in the final rinse when scouring it (or washing).  


That's the other thing, are you washing the wool first?  

Unwashed wool can attract pests like rats, mice, other things that like eating seeds (sheep are messy and lots of seeds get in their fibre) as well as bugs like carpet beetles, moths, and things that nibble on protein.

Washing the wool reduces the chance the bugs or critters would be attracted to the wool.  It also makes it very easy to add borax to the wool at this stage.  Not sure it would need special equipment, but you say you are in Europe and the health and safety stuff is much stricter there than here.  


Then there is the question of fluffing it up.  My understanding is that carded or willowed wool has a much higher R-value than compact wool off the sheep.  

Just out of curiosity,

You say you have access to wool. But you didn't mention if you have the ability to sell the wool. If you can sell it, why would you use it in such a way? Is it cheaper to use the wool in building, than the money you could sell it for?
And another question. Is wool used there for insulation? If so, how do they do it? Maybe you should ask the local builders, or the local historical society about wools use? Wouldn't that make sense to find out what is best in your own situation and environment, -then asking folks a continent away?

Jim Fry wrote:Just out of curiosity,

You say you have access to wool. But you didn't mention if you have the ability to sell the wool. If you can sell it, why would you use it in such a way? Is it cheaper to use the wool in building, than the money you could sell it for?
And another question. Is wool used there for insulation? If so, how do they do it? Maybe you should ask the local builders, or the local historical society about wools use? Wouldn't that make sense to find out what is best in your own situation and environment, -then asking folks a continent away?

Most of North America and much of Europe, wool is a waste product.  Here, it costs more to ship it to the mill or buyer than they get for the wool, so they usually burn or compost it.

Wool for insulation in Ireland goes back to at least the 1st century, probably long before.  Wool is a traditional insulator in many traditions around the world.

However, in between wall insulation stopped using wool due to health concerns as things like anthrax and pests can grow in it if it isn't cleaned.   It's only in the last 20 years - when people started looking for new uses for wool - that the industry started exploring wool as insulation again.   Something to do with the air-tight nature of the modern housing.  Not sure it would be an issue in a natural house build like described here.  

There are quite a few threads on permies that go into this in more detail.  This might be a good starting place.
https://permies.com/t/45846/Sheep-Wool-Insulation-talk

Thanks for the reply.

I’ve not yet used the wool.   The workshop is 15m x 5m.  It’s a lot of fleece to insulate.  I am not sure I could wash that quantity.  The initial idea was to lie the fleece out on the clean floor and spray it with the borax substitute, leave to dry and then use it.  I had intended cutting out dirty areas and pulling the fleece to fluff it out.

I have three bales of raw fleece sitting in the barn, two years now and no sign of pests in it . .  . They are probably waiting for me to use it in the roof before they get stuck in!

John

Jim Fry wrote:Just out of curiosity,

You say you have access to wool. But you didn't mention if you have the ability to sell the wool. If you can sell it, why would you use it in such a way? Is it cheaper to use the wool in building, than the money you could sell it for?
And another question. Is wool used there for insulation? If so, how do they do it? Maybe you should ask the local builders, or the local historical society about wools use? Wouldn't that make sense to find out what is best in your own situation and environment, -then asking folks a continent away?

Local wool price is very poor, hence I am able to get it of neighbouring farmers very cheaply. I have a small flock myself and it’s not worth even trying to sell it and I o my own shearing.

Local advice is treat with borax.

Commercial wool insulation is chemically treated and processed into batts similar to other insulation materials.  It’s not cheap!

Asking outside of the box can produce valuable insights not seen inside the box.

Local experts informed me borax substitute is no good.

Thanks for the reply.

There are quite a few threads on permies that go into this in more detail.  This might be a good starting place.
https://permies.com/t/45846/Sheep-Wool-Insulation-talk

I found this after I posted.  Thank you.

I hoped more recent updates may come to light.

Thanks again.

Just so we are on the same page.  A bale here is about 120-160 kilos of wool.  Is that the same there?

Cleaning that much wouldn't be too tricky, but finding a place to dry the wool would.  But then again, raw wool holds a lot of moisture.  Wool can easily hold 30% of its dry weight in moisture without feeling wet and yesterday I got some fun dealing with wool rot for a fleece that got put away before it was dry enough.

With an old bathtub, you could give each fleece a dunk in a soapy-borax mix then lay it out to dry.  

Willowing would probably be the least effort way to fluff up the wool.


For spraying, I'm thinking it's worth a test.  Get a kilo or two and see if the spray can soak into the wool.  Grease and wool both repel water - thus the awesomeness for fishermen's sweaters.

Oh, another idea for cleaning.  Rain.

Fisherman and Cowichan traditions both use this technique.  Lay the fleece on the hedgerow (hang from the pointy trees) or on the bushes.  Leave them in the rain for a month.  This gets rid of most of the dirt and sweat, leaving the lanolin intact.  

But 200+ kilo of wool... that's a lot of hedgrow.  might not work for this project.  

r ranson wrote:Just so we are on the same page.  A bale here is about 120-160 kilos of wool.  Is that the same there?

Cleaning that much wouldn't be too tricky, but finding a place to dry the wool would.  But then again, raw wool holds a lot of moisture.  Wool can easily hold 30% of its dry weight in moisture without feeling wet and yesterday I got some fun dealing with wool rot for a fleece that got put away before it was dry enough.

With an old bathtub, you could give each fleece a dunk in a soapy-borax mix then lay it out to dry.  

Willowing would probably be the least effort way to fluff up the wool.


For spraying, I'm thinking it's worth a test.  Get a kilo or two and see if the spray can soak into the wool.  Grease and wool both repel water - thus the awesomeness for fishermen's sweaters.

Bale size - 100kg max.  Due to the low value of fleece, it’s not really baled carefully so it depends on the bags available to the farmer.  They reuse all sorts to avoid incurring additional costs.

A bath dunk makes sense but it is the problem of getting borax now that it is restricted to certified professionals.

Drying will be an issue here - it’s always wet!  I hoped it would dry on the floor with good air flow (it’s also very windy!)

What is willowing ?

I will give spraying a go to see on its effectiveness.  It was recommended to me on an Irish based forum (by someone also recommending borax substitute!)

r ranson wrote:Oh, another idea for cleaning.  Rain.

Fisherman and Cowichan traditions both use this technique.  Lay the fleece on the hedgerow (hang from the pointy trees) or on the bushes.  Leave them in the rain for a month.  This gets rid of most of the dirt and sweat, leaving the lanolin intact.  

But 200+ kilo of wool... that's a lot of hedgrow.  might not work for this project.  

Lanolin is okay left in?

That's a tricky bit.  here borax is a common laundry item and necessary soil amendment so I can buy it by the kilogram at the grocery store or by the 25kilo at the farm store.

I wonder if it's "restricted" in the same way that many things here are.  If you can prove it's for agricultural or building use, you can buy it.  Might be worth asking at the local farm shop.  

Willowing

John Wilkinson wrote:

r ranson wrote:Oh, another idea for cleaning.  Rain.

Fisherman and Cowichan traditions both use this technique.  Lay the fleece on the hedgerow (hang from the pointy trees) or on the bushes.  Leave them in the rain for a month.  This gets rid of most of the dirt and sweat, leaving the lanolin intact.  

But 200+ kilo of wool... that's a lot of hedgrow.  might not work for this project.  

Lanolin is okay left in?

Opinions are divided on this.

There's a long history of industrialization changing how we think of wool and what's okay.  Basically, if you are using a 3-tonne machine to process the wool, no.  all grease must go.  For everything else, the answer is "It depends, try it and see what works for you"

200 kilo of wool is a lot of wool for someone new to processing it.  I think there will be some give and take between the ideal insulation (scoured, treated, carded, compressed/quilted)  and what is feasible.  

r ranson wrote:That's a tricky bit.  here borax is a common laundry item and necessary soil amendment so I can buy it by the kilogram at the grocery store or by the 25kilo at the farm store.

I wonder if it's "restricted" in the same way that many things here are.  If you can prove it's for agricultural or building use, you can buy it.  Might be worth asking at the local farm shop.  

I will give this a go.  My local farm shop is very helpful.

I’ve been building the workshop mostly single handed for nearly three years.  I’m resigned to the insulation in the roof being a slow job!

Willowing the fleece may do me some good having watched the video!  I’m a firm believer in the ‘Slow’ movement.

I'm very interested in how you get on John - we have similar issues here with waste fleece and expensive sheep' wool insulation. As well as the processing to make the fleece into a homogeneous product I gather most are also mixed with plastic fibres to give consistent loft. It does seem like a real opportunity to join the circle making use of a waste product  - win-win, but certainly in a house (which we are considering) I am worried about the possibilities of moths moving in.
I think the main problems with Borax are to do with it being used in laundry and the associated contamination of water, so if you were using it for building and didn't have too much liquid waste to dispose of you may be able to buy and use it OK. I did find at least one site online here, which might be worth a try. They do say:

This product has been reclassified by the ECHA as Reprotoxic Category 2 and as such is not available to the general permies. Borax can only be purchased by Professionals and by trade and business users or for scientific research.

but I don't know what checks they might do, so it may be worth a shot as a known good treatment that isn't too toxic when used responsibly.

I use raw wool in all my outbuildings, and sometimes even in our home.

I say raw, but I actually ferment it in a large trough of water for a few weeks, rinse it in rainwater or the creek, and let it sun-dry on a concrete slab.  It is my understanding that this cleans some, but not all the lanolin off, removing grime, and leaving an even protective coating.  

It started as an experiment 5 years ago, and I have been pleasantly surprised to have zero problems.  No pest, no odor, just an incredibly high-performing loose-fill insulation material.

Nancy Reading wrote:I'm very interested in how you get on John - we have similar issues here with waste fleece and expensive sheep' wool insulation. As well as the processing to make the fleece into a homogeneous product I gather most are also mixed with plastic fibres to give consistent loft. It does seem like a real opportunity to join the circle making use of a waste product  - win-win, but certainly in a house (which we are considering) I am worried about the possibilities of moths moving in.
I think the main problems with Borax are to do with it being used in laundry and the associated contamination of water, so if you were using it for building and didn't have too much liquid waste to dispose of you may be able to buy and use it OK. I did find at least one site online here, which might be worth a try. They do say:

This product has been reclassified by the ECHA as Reprotoxic Category 2 and as such is not available to the general permies. Borax can only be purchased by Professionals and by trade and business users or for scientific research.

but I don't know what checks they might do, so it may be worth a shot as a known good treatment that isn't too toxic when used responsibly.

Hi Nancy,

Slightly worryingly, I went to the site you had provided a link to and ordered 5kg of the stuff.  The order went through without any questions or checks!

Next hurdle will be to see if it is allowed to be sent to me across the Irish Sea!

Thanks again.

John

Beau M. Davidson wrote:I use raw wool in all my outbuildings, and sometimes even in our home.

I say raw, but I actually ferment it in a large trough of water for a few weeks, rinse it in rainwater or the creek, and let it sun-dry on a concrete slab.  It is my understanding that this cleans some, but not all the lanolin off, removing grime, and leaving an even protective coating.  

It started as an experiment 5 years ago, and I have been pleasantly surprised to have zero problems.  No pest, no odor, just an incredibly high-performing loose-fill insulation material.

Thank you for this comment Beau.  Very encouraging!

I like the idea of fermenting it. Washing wool uses crazy amount of water.
I used wool underneath of my small garden pond, covered with pond foil. Of course I didn't care about washing it or anything. The fish survived a winter and reproduced in that pond. Some parts of the edge are strangely fluffy. I will refurbish parts of the edge this winter or spring. I think most of it hasn't decomposed and it doesn't seem to compact much, despite the weight of water.

Fermenting is awesome.  

For insulation, a single dunk in soapy (even better if it's hot) water would probably get most of it out.  But if you can go further, even better.  

Sometimes we can get free old bathtubs here and some farms use a system with two or three bathtubs.  one for washing, the others for rinse.  Then when the washing water gets too dirty, the first rinse water gets some soap and becomes the washing water.  

The Big Book of Handspinning goes into detail on this method and how to save time and water washing large quantities of fleece.  (50+kilo in a batch)

What a fascinating thread. I have no sheep or wool, but I want to use wool as insulation. And, off topic, but I love my wool comforter, wool mattress, wool sweaters, wool t-shirts, wool blankets, wool pants, and cashmere too.

r ranson wrote:Fermenting is awesome.  

For insulation, a single dunk in soapy (even better if it's hot) water would probably get most of it out.  But if you can go further, even better.  

Sometimes we can get free old bathtubs here and some farms use a system with two or three bathtubs.  one for washing, the others for rinse.  Then when the washing water gets too dirty, the first rinse water gets some soap and becomes the washing water.  

The Big Book of Handspinning goes into detail on this method and how to save time and water washing large quantities of fleece.  (50+kilo in a batch)

I worked a hempcrete insulation job (outer walls) in Colorado where the homeowner used cleaned sheep’s wool as insulation between the roof rafters and inside wall framing.  Plastic was installed over the area to be insulated and reinforced using folds to keep the plastic from ripping away from the staples on each stud and rafter.  A leaf blower and hose system was rigged up to blow the wool into the void.  It worked really well, fluffing up the wool as it traveled through the flexible pipe. My concern was settling of the wool that could possibly create cold spots.  The shed roof pitch was low so that might not be a huge concern.  Heat loss was not much of a factor with the interior vertical wall framing.  The owner made the decision to go with wool rather than hemp wool (available in the States from Hempitecture) because wool had a slower burn rate/combustion rate than hemp wool in case of a fire (according to her research).

Dave Pence wrote: A leaf blower and hose system was rigged up to blow the wool into the void.  It worked really well, fluffing up the wool as it traveled through the flexible pipe.

What an excellent innovation for installing the wool.  My intention was hand installing knowing it would be a tedious job.

Do you know if the wool was treated first?

John

When we get our sheep shorn we have to find a use for it on the farm as it really has little value. We started using it for insulation in the back wall of our greenhouse, wall is 18 inch cavity so it takes a lot to fill. So far I would say it’s working, no wet sheep smell even in that high humidity environment. It is oily and heavy so I used plywood sheeting. Hope this helps some

As usual, this site provides tons of useful content on areas of exploration that the commercial world tends to ignore.  I really like the idea of fermenting the wool to get rid of infestations.  I see that borax has at least two formulations, borax pentahydrate and borax decahydrate.  It sounds as though the pentahydrate is the more active form and would be the best bang for the buck.  

If they only want to sell to a business, how hard would it be to set up a business experimenting on novel construction methods?  Just a thought.  As to drying the wool, do you have any farms around you that grow hay?  It might be useful to use a hay tedder on a field to lift, turn the wool and add loft all at one pass.  Another way to dry the wool would be to hold it above the floor in a barn and use a large fan blowing through the aisle.  That is a tried and true way to dry hay to reduce the potential for spontaneous ignition on farms around my neck of the woods.  Our weather is notoriously hard to predict and sometimes the forecast changes by the hour to attempt to keep up - it rarely does.  Rain seems to be drawn to recently mowed hay fields.

Good luck.  Hopefully the blower placement method works, it sounds really useful to reduce both effort and potential voids.

I’ve been using raw wool as mulch under fruit trees and garden plants. It is from sheep raised for meat and is filthy, which is good for decomposition. I’ve wondered about using it for insulation and other clean purposes. Instead of the wool being fluffy and settling, my inclination is toward felting. There is a video of “box felting” in which raw wool is cleaned during the felting process. The lanolin is retained, making it water resistant. There are also videos of rug making. On a larger scale, perhaps wool can be laid out and stomped on for felting and cleaned with water, but not soap. Shoes with spikes would help felting, like a crude needle felting. There is a US company that creates wool pellets for soil amendment, especially for containers to retain water. Probably too costly for insulation, but they wouldn’t compress. Just some ideas for experimentation. I think finding uses for this typically waste wool is good work.

Nancy - You have proven my contention that permies provide a wonderful think tank.  What about using the raw and even filthy wool to compress into liners for hanging baskets.  In northern regions, it would be locally accessible and replace the need to buy coca fiber to line the baskets.  I could imagine pressing the wool into pots for growing seeds.  It should be as good as cow manure pots for planting without removal as the roots of the plant should slide right through.  Making frost caps from raw wool for plants recently moved into a garden would utilize the fact that wool absorbs moisture and releases heat to protect from frost.  Think of making wool jackets for your tender plants along with wool socks.  Evening musing.

Interesting stuff.
I also have a workshop in the making which will have wool as roof insulation. Some wood waste product in the walls.
We used raw wool to insulate the walls and roof of our hen roost and it works well. I’ve heard no complaints about beasties from the birds but they always appreciate bit of protein.
When it gets real cold which it does, we live in the north of Sweden lat 63.96 N, I give the space a blast with a car heater and the heat holds pretty well.
Wool is great stuffed in around window frames too. And on the garden as a cover/mulch, quite amazing really.
As to washing, we’ve just picked out the least shitty bits. When we do wash the wool we use a tiny bit of linseed oil soap.
That’s my tuppence.
In addition ‘slaked lime’ can be added to the wool to control infestations, mice etc. That’s a tip from another trusted wool enthusiast, that we we’ll use next project. She just sprinkles it on as I understand.
Thrupence.

I don't know about using wool as an insulation because even if it is cleaned if it gets wet it can cause more problems plus it does breakdown over time. I would also think that the cleaning process to remove all the potential insects/their eggs, harmful bacterias and so on would be rather expensive today. I would opt for a soy based spray foam type if you can afford it.
But if you have lots of wool left overs after shearing try using this in the soil as pellet fertilizer and as a moisture holding medium. We have a company here in California that produces these pellets. Maybe you could start a home based business with the wool.
Here is their info: www.integrityalpacas.com, email charlene@integrityalpacas.com

Welcome to permies, Scott!  A few things your post makes me think about.  The main thing:

Scotttt Davis wrote:I would opt for a soy based spray foam type if you can afford it.

I think developments in biologically grown blown insulation are promising, but it's hard to work with soy without dealing with some things that many ecologically-minded folks tend to avoid.  For a better alternative, consider mycelium insulation.

even if it is cleaned if it gets wet it can cause more problems plus it does breakdown over time.

This is true of all insulation.

I would also think that the cleaning process to remove all the potential insects/their eggs, harmful bacterias and so on would be rather expensive today.

rainwater+time=free.

For those of you using wool as a mulch it has a great fertilizer analysis, 9-0-2.

Steve Picker wrote:For those of you using wool as a mulch it has a great fertilizer analysis, 9-0-2.

Hi Steve, What does 9-0-2 refer to?

Nitrogen- phosphorus-potash BPK when you’re talking fertilizer analysis

Build some Horizontal Bee Hives! They are insulated with 7 lbs of Raw Wool stuffed in the cavities between the inner/outer walls of the hive. The 2" X 2" framing structure leaves those voids. The wool insulation keeps the bees warmer during winter and cooler during hot summer days.

Free plans to build these hives is on the site at:   https://www.horizontalhive.com/

I have about 30 Finn sheep.
I gave all my extra wool to wheaton labs in montana



a good dusting with food grade diatomaceous earth (DE) and stuffed in the walls and ceiling of the red cabin.  

The cabin was fully built, but a bit drafty.  I think they just stuffed it in around the existing insulation and now it is super cozy.

The pump house at wheaton labs has a mycoinsulation roof.  I think the plan with the walls is to stuff burlap sacks with wool and staple them between the studs as the exterior wall boards are going up.


we did not wash any of this wool.  It is a bit dirty with bits of straw.  some is partly felted     dusting it with DE will keep moths and other insects from being a problem

Lanolin is also a partial protection against pests.  Raw wool is much less subject to insect damage than finished wool articles.  (but not immune)  The downside is that the wool is less likely to absorb whatever other insecticide product you put on it if it is not clean first.

I've used the fermentation and the rainwater methods.  Fermentation is faster and easier to keep your wool separate from other contamination.  Rain is very easy, but you may have twigs/grass/dirt in the fleece afterwards depending on where you hung it.  Laying it out on screens or a canvas might be a good option.