Sheeps wool insulation

[Herefordhouse]

When it comes to sheeps wool insulation, people talk about the potential requirement to card it (combed). Is this a necessary step? I have access to free sheeps wool and am looking to insulate my loft space, which is likely to remain unused.

Would i be able to just clean the wool, treat it with borax for pests and then fit it uncarded? I could apply it thickly between floor joists to an estimated thickness of 280-300mm and i believe i will get sensible U value improvements.

But if i have to also card the wool to get the correct properties i dont think this is worth the time investment.

 

[aockenden]

What is the reason that "carding" is supposedly necessary? Like what reason do these carding-advocates give for their belief that it's necessary? If they say that until it's been "carded" that it won't insulate properly, I say that's a load of bollocks. Do sheep freeze to death in the Welsh hills during winter unless their wool is shaved off, "carded", and then wrapped back around them and duck-taped in place?

 

[Herefordhouse]

this was my thought. If you wash the wool and then apply a pesticide as required then when it is air dried whats wrong with that as a finished product. I think it comes down to time vs cost

 

[aockenden]

this was my thought. If you wash the wool and then apply a pesticide as required then when it is air dried whats wrong with that as a finished product. I think it comes down to time vs cost

Sure, and if we do believe that "carding" would somewhat improve the insulation value, then you can always just double-up your thickness (seeing as you're getting it for free anyways) and make up whatever difference that carding would actually impart.

I'll be putting some in the loft of an outbuilding we're converting into a work-office annex, and I'm just going to wash it, (maybe with Borax, maybe not), and that's it. No other treatement. I want to see what the bare-minimum requirements actually are here (I'm guessing they're quite low indeed).