Sheep wool insulation?

[rippie]

Does anyone have any experience with sheep wool insulation? Or any other fiberglass alternatives? I am considering it for the wall/ceiling areas with foam board below the subfloor, maybe with some reflectix thrown in here and there for good measure. The wool is treated for pest resistance.

[Stefrobrts]

I used to have sheep and llamas, and I have heard of a lot of uses for wool, but that is one I have never heard of. I guess I would wonder about it compressing over time from moisture/condensation, and the vibration of going down the road.

[perryg114]

Use foam board everywhere. I would be concerned that it would be heavy and also degrade over time. I am thinking rotting falling apart and eventually becoming a growth medium for God know what after the preservatives are not longer effective. Think of fiberglass as wool made of glass instead of hair. The fiberglass is biologically neutral.

Perry

[rippie]

Hi Stephanie
The wool can be made in batting form, which looks like fiberglass. It does have some ability to get wet and dry out. But due to my unpleasant belly pan experience, I would not put it in the belly. I dont think the compression would be that much of an issue.
Anyway I am leaning this way and I only have the rear bathroom/closets exposed for reinsulation. I just don't want to use this if someone else has any horror stories or if a better tried and true low toxicity alternative may exist.

[rippie]

Perry
You may be right about the treatment degrading over time. I'll have to inquire about that. If fiberglass is so neutral, then why do I have to dress in Haz Mat garb (gloves, respirator, body armor) to deal with it?

[Stefrobrts]

Because it is made of glass, so tiny shards of it could get in your eyes, stick in your skin, etc. Though I have worked with fiberglass for small projects and not experienced any issues, just using long sleeves, a mask, and safety goggles. But bacteria and mold will find nothing to feed on in the glass strands, so that's one reason it might be better than wool.

Remember once you seal it up no one will probably disturb it again for a very long time.

[Melody Ranch]

Kapok.

[rippie]

Stephanie
Sheep wool is naturally resistant to bacteria, mold, fire, and dust. And its non toxicity means you can handle it without all the protective materials, which is nice. And, in my opinion, it would be safer to breathe.
I have doubts about anything being sealed and staying in place in an airstream. I keep hearing how all airstreams will eventually leak water. I have experienced this first hand. And think how much engineering and efforts have gone into water resistance. I don't think anyone would claim that their cabin was airtight ever, or ever will be.
So it must be assumed that the forced air circulation will cause some stirring up and mixing in of insulation into the cabin (at varying degrees). So in my case I would prefer to be exposed to the hair over the shards any day. I am not saying that Sheep Wool is the perfect insulator for these reasons. But I am also not guessing that it is not.
Does anyone have actual experience or first-hand knowledge to share?

M. Ranch
Have you used kapok? Seems the flammability would be a concern to me.

[Stefrobrts]

I'm not saying you are wrong, I'm just saying I have never heard of it being used that way. And I've spent a lot of time around 4H wool judging, spinners, other farmers, and even a friend who owned a wool mill for a time, and insulation is not one of the uses I ever heard anyone bring up.

I am always open to other uses for things that we may not know about. I'm curious to hear if you find any more about it, but I don't think you are going to find anyone here who has insulated their trailer with wool. We have from time to time had people who were working on ultra-green projects, or projects with only natural materials to avoid exposure to modern products they were allergic to, so there might be some alternative solutions out there.

[rippie]

Thanks Stephanie
I think only time will tell. I am pretty sure that no one has any long term reports of its success in a trailer yet. But I am very interested for two reasons: 1) I have moderate respiratory allergies and 2) I have a trailer without insulation ready to go.

I am really looking for a "definitely don't do this because..." experience. I thought someone in the forum may have insulated their home with it. Which is just slightly more conventional, but not much.

Here is a link for anyone interested to someone who has done this:EcoLocalizer | News & commentary on sustainability, activism, urban planning, politics, and our world.
Which again, doesn't itself sell me on the idea. The fact that the dog is so comfy is cute. But then almost immediately I began to imagine all the little mice who might also
find it agreeable. The company I talked to is called Oregon Shepherd, if anyone is interested/ curious. For me, I guess I am leaning this way but not 100%. Still haven't found out how long the insect resistance is purported to be.

[SteSpot]

I don't have any experience using wool insulating trailers but I can tell you that my wilderness survival instructor only allowed us to bring a wool blanket for our survival weekend due to the fact that wool will still keep you warm even when wet (unlike down). Since then I have used wool socks for hiking and skiing and my feet are always warm even with perspiration (unlike cotton). I have wool sweaters that are the best for keeping me warm.....I would think it would work in the walls of a trailer as well. Let us know how it works.....paula

[cameront120]

I'm not sure I'd want to use any organic compounds within the wall cavity of a trailer. Once wet (not if), it will become a medium for mould growth (mould resistant isn't the same as mould proof). Using it in a house is different because of the current use of rain screen systems to keep water from reaching the insulation cavity.

[perryg114]

As Stephanie said, it is because of the glass particles that can be inhaled and also get into your skin. I HATE working with the stuff. You should try crawling around in a hot attic. Any type of woven material glass or wool is going to get wet and hold water against metal and wood surfaces and eventually serve as a great growth media for fungus and mold and also provide warm nests for rodents. A lot of bad the smell in old Airstreams is from wet insulation and all the stuff that has grown in there over the years. You wool might be coated with flame retardants that are toxic.

Perry

Originally Posted by rippie

Perry
You may be right about the treatment degrading over time. I'll have to inquire about that. If fiberglass is so neutral, then why do I have to dress in Haz Mat garb (gloves, respirator, body armor) to deal with it?

[rippie]

Agreed Paula. Wool is some great stuff. I used it for cloth diaper covers for my earlier kids. It has some truly amazing properties and is a superior fabric for clothes. That being said, that makes me cautious that I may be overextending my fondness to an area where it could prove inadequate.
Cameron, you make a good point. Especially because wool has such good wicking properties, I think it should not be in contact with the floor, of which my c-channel became sort of a rodent bath. I think a short, non-permeable foam layer here would work well all around. I hadn't thought about that.
Perry, if a cover of reflectix with foil tape can create a water resistant barrier all around on the outside, I think the structure/function may be ideal. I just pulled all the (what I think is original) insulation. It was in amazing condition. I don't see any sign of leaks. As for the wool, the only treatment is a fusing of borax with the fiber. As far as I know, this is the same thing some people use as a laundry aid & others as a natural way to deter ants. It may also have some fire resistant properties but is not toxic. And I called to ask about the treatment wearing off. To which there was not any real specific information given. That is definitely still a concern to me.
Thanks for all the comments. It is really helping me think things through.

[perryg114]

The skin of the trailer is water resistant. There is a lot of controversy as to how well you want to seal things. The trailer walls will sweat and there will be leaks from time to time. Where is the water going to go? It should end up in the C-channel at the bottom of the walls. You want to prevent large pockets of air that can convect heat but you also want things to breathe to some extent. I taped all seams of RMAX ridged foam but left the bottom edge unsealed. This prevents air from moving around but leaves a place for water to go. At the bottom of the C-channel, I put in drains so water has a place to go other than the floor. The reflectix stuff and similar products work best when there is an air gap on both sides of it. You could use it as a top layer to foam insulation. The RMAX has reflective aluminum on one side and painted aluminum on the other side so it also acts like a radiation barrier as well. All of these insulating materials that are not radiation barrier materials, use air to insulate by separating the air into little pockets where it can't transfer heat well from convection. The radiation barriers work by reflecting heat back where it came from and also keeping it from radiating to the cold side. If something touches the surface, then it does not work as well because now conduction is shorting out the radiation barrier. You don’t have enough room in the walls of an Airstream to have much of an air gap on both sides. Also the radiation barriers only work when they stay clean and shiny.


Boric acid is used to preserve wood and fabrics and it will wash out and I am not sure what the acid will do to the metal. It is also a flame retardant. Stuff that is preserved this way will develop that old canvas tent smell.



Perry

[JeffBear]

Hey Rippie,

I know it was a long time ago but did you end up going with sheep wool for your insulation? And if yes, how is it going on after a few years? My wife and I are restoring our Airstream and would like something more natural that the usual insulation.

If anyone else stop by and have some experience with sheep wool (or cork insulation), I'd be happy to hear more about it :-).

Best,
Geoffrey