For millennia, people have used the wool from sheep to keep warm. They may weave it into blankets or warm clothing, and some have created wool filling to stuff blankets, clothing or mattresses. It’s not surprising that groups like nomadic tribes in Mongolia have also employed wool as insulation in homes, and this idea has translated on a much larger scale to commercially produced wool insulation.
This form of insulation is sheep wool that may be treated with materials like borax, and it can look similar to fiberglass insulation. The many people who choose wool insulation cite several of its advantages. It naturally resists flame and fire, and it can trap chemicals that are known toxins. Another advantage is that sheep wool is biodegradable, though processes used to raise sheep are not always environmentally sound. However, raising sheep tends to incur less environmental debt that does, for example, the production of fiberglass.
One benefit to wool insulation is cost of installing it. Unless a person is allergic to wool, there is no need to wear protective clothing during installation. This can lower the cost and duration of installation time.
Another of the benefits of wool insulation is its ability to absorb water without losing its insulation capacity. When fiberglass or cellulose insulation gets wet, it becomes fairly ineffective. This does not apply to wool and may make this insulation a better choice in some instances.
Wool insulation is considered very effective in insulating homes, and potentially more effective than fiberglass. It tends to dampen sound, which might make it an attractive insulation choice in homes sharing connecting walls. However, the insulation itself is usually more expensive than fiberglass, and in some parts of the world it may be difficult to find builders that are familiar with using wool insulation. For instance, though a few US builders are now using wool, the majority use other insulation forms. There is a larger percentage of use in Australia, Europe and Canada, which may definitely influence US building practices in the future.
Some argument exists that those unfamiliar with wool insulation would be less likely to install it. Yet installation is similar to fiberglass and is not difficult to adapt to. Wool insulation comes in several sizes, and is suitable for insulating between inner and outer walls and in floors and roofs.
One potential area of concern with those looking for environmentally friendly building practices is chemicals and pesticides to which sheep are routinely exposed. In most cases wool is washed prior to being constructed into insulation, but this creates its own issues. Chemicals that are washed off can contaminate groundwater. People looking for alternatives to fiberglass who are not interested in wool may want to consider products like cellulose insulation.