Improving efficiency

[Garald]

24 minutes ago, Mike said:

 a natural insulation (but not sheep's wool) may be better.

 

 

Wonder why you specified *sheep's* wool. Never heard of llama wool being used for insulation. (Now that's an interesting idea in certain circumstances, but I'd imagine the problems would be much the same, no?)

[SteamyTea]

4 minutes ago, Garald said:

Never heard of llama wool being used for insulation

My parents had a holiday in Peru, they said the villages with Pushmi-pullyus in them smelt really badly.

Edited January 24 by SteamyTea

[sharpener]

1 hour ago, Mike said:

In other circumstances, a natural insulation (but not sheep's wool) may be better.

 

Yes the absorption/desorption of moisture can be useful. What have you got against sheep's wool?

 

Our bedroom had penetrating damp in the west-facing gable end wall. After taking advice inc our surveyor who specialises in traditional buildings we now have the following construction:

 

• Original 600mm stone wall
• 50mm batts of sheeps wool between horizontal 50mm battens at 450mm centres
• Plastic retaining mesh
• 50mm ventilated space formed by vertical battens, with louvre vents from the room at bottom and exhausted to MVHR plant at top
• Foil backed plasterboard and skim coat

 

Sheep's wool batts came from Bradford's depot at Evercreech Junction (former station on S & D). We have had no more problems with the damp. OH can occasionally detect smell of sheep's wool but I can't.

[Mike]

45 minutes ago, sharpener said:

What have you got against sheep's wool?

 

Nothing when used to insulate a sheep.

 

But, for buildings:

https://www.telegraph.co.uk/news/2017/09/01/grand-designs-dream-home-ruined-biblical-plague-moths/

https://victorianhouseproject.blogspot.com/2019/11/moths-problem-in-sheep-wool-insulation.html

and other occasional similar reports dating back many years.

 

Although there are anti-moth treatments used - Borax seems popular - I've not yet seen an academic paper confirming its efficacy. But if anyone can point me to one, I'd be interested.

[Garald]

Right, that's what I've heard. But then I'm sure some bugs like cotton, linen and hemp - wonder what is added to BioFib Trio to prevent that.

[Leopold1904]

I suspect this discussion would be better in a different thread, but briefly, I'm thinking of using PU to insulate a couple of attic rooms, which will be outside, as it were, ie, I'll insulate the walls and the floors from the rest of the house. This does mean we will need to be able to walk on the insulation since we use the attic for storage, so PU, I suppose. And of course we won't be unduly concerned about the air quality. I'm still trying to work out the logistics of having an inward-opening door into these rooms since I'll either have to cut off the bottom of the door (don't really want to do that) or have an uninsulated space where the door opens. Or some sort of Heath Robinson mechanism that lifts one of the PU panels when the door is opened...

[Mike]

17 hours ago, Garald said:

I'm sure some bugs like cotton, linen and hemp - wonder what is added to BioFib Trio to prevent that

 

Clothes moths get their protein from animal fibres (keratin) not plant fibre (cellulose) so it's not a problem. Termites would be a bigger threat, but it's been tested against them (and clothes moths) to ISO 3998-1977 - https://cdn.chausson.fr/catalog-document/56ff46a2-72ab-4dcd-800c-7cba0040e887/certifications-813061.pdf and passed. Since France does have termites in some regions it's very likely that any problem would have become evident by now.

[Mike]

8 hours ago, Leopold1904 said:

This does mean we will need to be able to walk on the insulation since we use the attic for storage, so PU, I suppose

If you lay MR chipboard or similar over it that would work. For other insulations, check out LoftZone StoreFloor.