A friend recently passed me a clipping that she had kept from the Daily Mail newspaper, about a lady who was living in an energy efficient house that she'd insulated with lamb's wool. This immediately captured my attention, as we are planning to insulate our house before the winter sets in. These days you have to do everything you can to keep the heating bills down, and living as we do, in a high-ceilinged Victorian House, that can be doubly challenging.

Anyway, I decided to do some research into this form of insulation as I like the idea of choosing a low carbon solution that comes from a natural and sustainable source. After all, even if it doesn't grow on trees, it does grow on sheep! Soon I discovered other news stories about sheeps wool insulation, including one about the Bodleian Library in the University city of Oxford. Housing over 8 million rare and valuable books, the Bodleian is one of the most prestigious buildings worldwide, to have been insulated with Thermafleece, British sheepswool insulation. Oxford University Estates specifically selected Thermafleece because it is inherently compatible with tradional building methods, as well as having full building certification through the BBA. An extra consideration was the breathable attributes of natural wool fibres. The fact that they absorb and release moisture was a key factor in the decision.

Well, the more I found out about Sheeps wool insulation, the more I liked the sound of it. Here are some more of the benefits:

• Sheeps wool insulation (Thermafleece) is very warm, and can also be used as an acoustic insulator, or for caravans, motorhomes, or baths.
• Sheeps wool is good at dealing with humidity or dampness, as it can absorb moisture from the air, then release it later, without going mouldy, and meanwhile it actually generates heat whilst moist. (A big plus for sheep?)
• It's naturally fire retardent (Also a big plus for sheep!) Wool does not readily ignite, it just smoulders, so this makes it an ideal insulant for timber framed properties and homes with thatched roofs.
• Sheeps wool insulation (Thermafleece) breaks down formaldehyde, a known carcinogen, into safe molecules. As many materials commonly used in construction contain levels of formaldehyde, this is very helpful.
• It's non-irritant (unless you're allergic to wool) so can be installed without special gloves or masks. The kids can even give you a hand! Have you ever tried handling the fibre glass alternative? Not so pleasant, believe me!
• It's available in a choice of thicknesses.
• It is a natural product

Sheep's wool has a very low conductivity, which effectively means that heat has a hard time passing through it. Laboratory tests have shown this form of insulation to be more effective than both Glass Wool or Mineral Wool. In a real-life situation, where humidity is also factored in, the results are even more impressive.

In existing houses in the UK, attics are required to have a minimum of 120mm insulation where sheeps wool is used. For new-build homes, this increases to 240mm thickness.

For internal thermal/acoustic purposes, www.sheepswoolinsulation.co.uk suggests a thickness of between 80-100mm between stud partitions, and for dormer/cathedral ceilings, a thickness of 200mm is recommended.

If you already have insulation in your attic, but it's been there quite a while, and it's the typical mineral wool or rock wool, the chances are it will have settled over time, and may not comply with new depth regulations.

If this is the case you can either take it up and replace it, or lay the new sheep's wool insulation over the top. Remember if you do take it up, it's a good idea to use gloves and overalls, and possibly a mask to protect against all those itchy fibres. Overlaying with sheep's wool has the benefit of not redistributing the old itchy fibres around the loft space!

Sheep's wool insulation( also known as Thermafleece) has an extremely low environmental cost, unlike some of it's competitor products, so it's definitely a very 'green' choice, quite apart from all the other benefits.

Further information about sheeps wool insulation (Thermafleece) can be found in wikipedia;

http://en.wikipedia.org/wiki/Wool_insulation

Ideally, insulation should hug your living space for maximum benefit. If your roof space is only used for storage, then insulate the floor. This saves the added cost of heating the whole attic. If, however, you have a loft conversion, follow the shape of the roof to ensure heat retention.

What about my water tank & pipes?

Water tanks and pipes need to be well insulated in severe weather conditions to prevent damage to plumbing. If you've insulated the floor of your roof space with Thermafleece, then you should certainly consider insulating the water tank, water tank cover, and pipes in the same way. Remember to leave the space beneath the tank uninsulated, so that warm air can percolate up from the heated part of the house, thus helping to keep the tank from freezing.