sheeps wool between rafter insulation

[karenandoz]

Hi - would appreiciate any advice on this one.

Getting ready to insulate vaulted ceiling of kitchen extension. We are going to use multifoil on underside of rafters, but reluctant to use cellotex type board or rockwool type product between rafters (my dad reacts to them).

I'm having problems finding comparisons for u-values etc. if we used sheeps wool, as to what thickness we would need? Also because of breathability of it would you need an air gap, or could we do full-fill(we have 6" rafters)?

I also once saw a product that was a non itchy, batt that was squishable, so that you got a really good seal against rafters - any idea? I can't find info on it again now!

Thanks in advance for any help!

 

[merlin50]

sheeps wool fire risk

 

[karenandoz]

hi - thanks for the response - apparently sheeps wool self extinguishes, so doesn't catch fire

 

[ladylola]

True, wool insulation doesn't burn unless the whole building is a huge blazing inferno. On the whole animal fibres smoulder then go out on their own.
I have installed lambswool insulation in the past and if I recall in came in slabs about 3" thick. Nice to work with ,doesn't itch, smells nice and you can even lie down on it for a nap, er if you want.
It is quite akward to cut we ended up using a sort of bread knife.
A word about the ventilation. Ventilation is generally a good thing in any roof however I'd be very careful to fit insect mesh on ALL ventilation points. We fitted wool to Stowe house (a public school) in Buckinhamshire around 6 or 7 years ago but a few years later they suffered an infestation of moths nesting in the wool and it all had to be ripped out and replaced with fibreglass. Luckily for me I wasn't involved in that part of the job.

 

[karenandoz]

Thanks ladylola - thats really good advice, as our roof design does have open eaves!