The only place I have ever been in with wool insulation was super drafty and full of moths. I don't know what kind of condition the wool was in when it went into the walls or how much care and experience was involved in the install but I was not impressed with the result. Not to discourage you. This place was in just about the wettest part of Washington and until my friend stumbled on it it was frequently unoccupied and subject to heavy use/no use periods. Just sayin' - Beware of Moths.
David Livingston wrote: I have never heard of sheep being bothered by moth infestations .
Several funny visions popped into my head when i read that . Wool is flammable also , we used to burn it when i was a kid to get rid of it when there was no market for it. put it in a pile and toss in a match and it went up fast. might be less flammable if it was washed to remove the oil i would guess, might be able to treat it with something to keep the moths out,and flame retardant like they do with cellulose insulation .
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I have to question this statement. It has been my experience that wool is actually quite flame resistant. I have not only experience it myself, but many others have suggested it. However, I only have knowledge of wool as a fabric (i.e. as a blanket, sweater, yarn, shirt, etc.) so perhaps if it is used as insulation it is used in a less altered and "puffier" state. Such as the difference between a cotton ball and a cotton t-shirt. Can anyone shed any light on this?
Wool will burn. It isn't the *poof!* up in flames sort of burn, but a decent fire will do the trick. Most of my experience has also been with woven wool (army blankets sweaters) and they tend to smolder - but a I bet if one was to hold the corner of an army blanket to an open flame like a candle you could get it to catch. The oils found naturally in unwashed wool would probably heighten this effect.
Wool will burn to some degree, but if there isn't another source of fuel keeping it going, it will self-extinguish. As far as moths go, they much prefer unwashed fleece. The reason they aren't found on sheep is that sheep are moving around, out in the sun and the wind. Moths live where it's dark and still, which is just what you'd have if you used it for insulation. I've heard of people using wool as insulation, but unless it's in an airtight space, moths are a very likely problem.
i wonder if mixing in some dried up lavander would repell the moths, and to what degree, would it be feasible on the long run, or just work for a year or three and then just act as a kindle? - i figure it would require a significant quantity of dried plant material...
It has been my experience that wool is actually quite flame resistant.
Raw wool in bulk is highly subject to spontaneous combustion.
I worked on an island whose principal source of income was exporting wool.
A ship came in to pick up the island's annual production.
The chief mate walked the docks with a thermometer probe, testing random bales.
It had been rainning for several days prior to their arrival.
Most bales on the outer edges were reading 140-160 degrees F.
The ship refused to load them, as they felt that the entire cargo would soon burst into an uncontrollable fire.
Wet wool ( key word, wet) in quantities can burst into flames, just like moist any organic matter. Hay is famous for it. If using it for insulation, like any insulation, one would probably use is dry, or at least in a situation where it could breath.
However, in normal conditions, wool is exceptionally flame resistant.
Travis Johnson wrote:Yes exceptionally flame resistant.
In order to make it suitable for insulation it has to be treated with borax to make it rodent and insect proof. I am however, unsure of the proportions. A google search should give you that though.
I think, I would say it's "preferable to treat it with borax". Keep in mind, wool has been used by humans for insulation (rugs, walls, &c.) for a few thousand years without being treated. Cultural patterns of use discouraged pests; for example, regular airing of wool in the sun, inspection, use, &c. These kinds of behaviors aren't normal for us in this day and age, so yes, it is preferable to treat with borax if we are using it for insulation. Looking at historical evidence, we can see that it's not, however, necessary.
Using google to discover the amount to use when treating wool is a bit tricky. Online, some sites confuse the ratios for treating plant fibres (like hemp and cotton) for fire proofing and apply this to wool. If memory serves, The Big Book of Handspinning has a more useful ratio of borax to wool for rodent proofing. I think it's a lot less than one uses on cotton for fire resistance.