Sheep wool insulation - any good and where to buy?

[BlueC]

Anyone used sheep wool insulation batts or rolls for under-floor or ceiling insulation? What's your thoughts on it? And does anyone know where to buy it? I can only find three manufacturers in the UK:

Thermafleece - everyone stocks this
Black Mountain - their factory has a 6 week backlog (!!)
Kontrol Insulation - not even sure if they still make it as can't find any info.

So looks like it is thermafleece, but are there any others?

Edit: just found NaturePro too that seems to be sold exclusively by Insulation Express.

 

[mattice]

http://www.lime.org.uk

We got ourselves a sheeps wool duvet - you could almost do without roof insulation ;-)

 

[skier-hughes]

I've used Thermafleece, it's brilliant to put down, but not sure if it's any better than really cheap insulation as we have a mix of different types and as rooms are totally different sizes and heated differently can't really be sure.

 

[BlueC]

Thanks to both. Lime looks a good site. We might use hemp insulation yet - not too sure. The main reason we want a natural one is for breathability to reduce the risk of condensation.

One thing that is crazy is that with sheeps wool/hemp we can't reach the U value required by building regs as our joists are only 100mm deep. To meet the required U value we'd have to use a PIR rigid insulation which is absolutely crazy because it is most unsuitable in terms of breathability and also practicality of fitting it between uneven joists. I'm hoping our BC officer is going to accept a compromise.

 

[Zebra]

Your BC officer might or might not be a fan of the stuff, but multifoils can sometimes help, and according to some sources, can allow you to use sheepswool insulation, and still achieve good U-values. Of course, it's not breathable, but if used on the interior faces of the joists, then the joists would still be able to breathe to the outside.
I take it you are not talking about ceiling joists where there is a loft above, as then depth wouldn't be an issue? I take it you are talking about a ceiling below a pitched roof?

 

[MatthewC]

I installed Thermafleece in my loft but, not having lived here before I did it, I can't say for certain how it improved the place. However, the upstairs has been pretty snug in the last two winters and I'm sure it had something to do with the Thermafleece!

It is indeed much nicer to lay than anything glass-fibre, but do a wear a mask anyway - I got a bad throat on the first day I did it, so waited a couple of weeks and did some more - bad throat again. Then I realized that it's the dust that gets disturbed which gets in your throat so the third time I wore a mask and it was fine. Cutting it is also an acquired art - I had a wooden board to rest the edge on, and cut downwards with a carving knife, which compacted it and cut well.

 

[paddytt]

We used sheepswool from Black Mountain in our living room and kitchen, and they hold the warmth better than the rear of the house, which had thick victorian solid brick walls. We also used it in part of our loft, and it's certainly worked!

regards

TT

 

[BlueC]

Thanks everyone. Sounds like sheeps wool is good but we're really struggling to find any the right size. Looking at hemp now but might have to import from germany which can't be cheap.

Zebra yes we're talking below the floor in a void. Ideally want to have it the correct depth then hold it up with a breather membrane stapled to the underside of the joists. Would rather have 10mm too much and compress it a little than 10mm too little and have air gaps.

Building control visited today and was happy for us to use hemp or sheeps wool, so now just need to source it!

 

[paulb33]

Zebra yes we're talking below the floor in a void. Ideally want to have it the correct depth then hold it up with a breather membrane stapled to the underside of the joists. Would rather have 10mm too much and compress it a little than 10mm too little and have air gaps.

I'm looking at exactly the same job. What membrane do you plan to use?

 

[Zebra]

I was asking about the ceiling construction, where you were talking about using it in a ceiling. Are we talking about the same thing, ie you want to use it between the downstairs ceiling and upstairs floor? You were originally asking about use in ceilings, which is why I was asking whether the ceiling has a loft above, or a pitched roof...

 

[BlueC]

Zebra yes we're talking below the floor in a void. Ideally want to have it the correct depth then hold it up with a breather membrane stapled to the underside of the joists. Would rather have 10mm too much and compress it a little than 10mm too little and have air gaps.

I'm looking at exactly the same job. What membrane do you plan to use?

Hi paulb33, any builders merchant will have their own brand "breather membrane" and they're all pretty much the same thing. They are used in roofing instead of felt. The important thing is that it is vapour permeable - you do NOT want a vapour barrier!

If you're doing the exact same job then this was a really useful article [1]. He recommends solitex plus as the membrane [2], taped with Tescon number 1 at the seams [3].

[1] http://www.greenbuildingstore.co.uk/page--insulating-suspended-timber-floors.html
[2] http://www.greenbuildingstore.co.uk/page--pro-clima-exterior-options1.html
[3] http://www.greenbuildingstore.co.uk/page--pro-clima-airtightness-tapes-options.html

Hope this helps

I was asking about the ceiling construction, where you were talking about using it in a ceiling. Are we talking about the same thing, ie you want to use it between the downstairs ceiling and upstairs floor? You were originally asking about use in ceilings, which is why I was asking whether the ceiling has a loft above, or a pitched roof...

I think we got confused, I did mention both under-floor and ceiling insulation. The actual circumstances are this:

1) Beneath ground floor, in between the joists above a ventilated void
2) Between floors (basement and ground)
3) Between floors (ground and first floor flat above)

So no, it is not a ceiling in terms of there being a roof or void above.

 

[Zebra]

Aha. Forget what I said about multifoils then. Which bit were you talking about, under-floor or between-floor, when you said this?

One thing that is crazy is that with sheeps wool/hemp we can't reach the U value required by building regs as our joists are only 100mm deep. To meet the required U value we'd have to use a PIR rigid insulation which is absolutely crazy because it is most unsuitable in terms of breathability and also practicality of fitting it between uneven joists. I'm hoping our BC officer is going to accept a compromise.

 

[BlueC]

Aha. Forget what I said about multifoils then. Which bit were you talking about, under-floor or between-floor, when you said this?

One thing that is crazy is that with sheeps wool/hemp we can't reach the U value required by building regs as our joists are only 100mm deep. To meet the required U value we'd have to use a PIR rigid insulation which is absolutely crazy because it is most unsuitable in terms of breathability and also practicality of fitting it between uneven joists. I'm hoping our BC officer is going to accept a compromise.

That bit was the beneath-floor (above void) where the joists are not very deep. In the end the BC officer was happy with my alternative suggestion.

Nearly ready to order now. Seems lime.org.uk is the manufacturer's site and they are the cheapest. Just wondering if anyone has views on Thermafleece Ecoroll vs Original?

 

[Zebra]

I used Ecoroll in my walls. Can't remember why. Thermafleece recommended it rather than original.

 

[BlueC]

I used Ecoroll in my walls. Can't remember why. Thermafleece recommended it rather than original.

Haha I had the same conversation with them yesterday. They basically said the normal stuff is a waste of money but some people prefer it as it is more pure.

 

[BlueC]

Just to finish this off in case anyone finds this topic in future. In the end I bought Thermafleece Ecoroll and got it from Natural Insulations (http://www.naturalinsulations.co.uk) at a better price than buying direct from lime.org.uk. Very pleased with the service - paid on Sunday, arrived by pallet courier on Wednesday as promised. The insulation seems nice quality and is much better to work with than rock wool, although you do still need eye protection and a mouth mask for comfort.

Spent the weekend laying it in the void beneath the house - not a nice job!! Early days but my feet are not freezing cold like they usually are right now so hopefully it has been worthwhile.

Thanks to everyone for their help.

 

[Willmatt]

Hi there, I went on a SPAB course a few years ago and recall it being reported by one of the professional tutors that the National Trust were ceasing using wool insulation products due to moth infestation! Unsure if this was true or not but think the insulation is supposed to be treated with borax or similar to reduce insect infestation so possibly it is a plausible story.

Would be interested if insect infestation is an issue?

Willmat

 

[BlueC]

Would be interested if insect infestation is an issue?

Not yet but it's only been installed for 8 hours!

Not sure but perhaps NT were using untreated wool? Thermafleece is treated with borax as you said so I am hopeful there won't be any problems.

Having seen under our floor I reckon a spider infestation is more likely! Crikey it was grim down there...

 

[LadyArowana]

Hi there, I went on a SPAB course a few years ago and recall it being reported by one of the professional tutors that the National Trust were ceasing using wool insulation products due to moth infestation! Unsure if this was true or not but think the insulation is supposed to be treated with borax or similar to reduce insect infestation so possibly it is a plausible story.

Would be interested if insect infestation is an issue?

Willmat

I am sure I remember the project manager at the SPAB townhouse restoration saying during our Open Buildings Day tour that they were using sheepswool, and that it had been treated for exactly this reason. IIRC he was explaining different options and the "green" credentials of each and said that because of the stuff they had to use on the natural one to prevent insects there were still downsides from an eco perspective.

 

[Moo]

You make me feel really ashamed, milady. I was standing next to you during the whole of that tour, and although it was fascinating I don't remember half of it!