Building insulation materials weak and brittle. Before its risks were recognized, it was used because it was a cheap, effective insulator with a high R-value and its open-cell structure was a good acoustic insulator. Though it absorbed moisture easily, it regained effectiveness as an insulator when dried. Asbestos once found common use as an insulation material in homes and buildings because it is fireproof, a good thermal and electrical insulator, and resistant to chemical attack and wear. It has been found that asbestos can cause cancer when in friable form (that is, when likely to release fibers into the air - when broken,
Wool insulation insulation, also called slag wool or rock wool, which only resembles natural wool fibers. It is actually made from rock, blast furnace slag, and other raw materials which are melted and spun into fibers. Sheep wool is a natural, sustainable, recyclable material, which is biodegradable, and has low embodied energy. It does not endanger the health of people or the environment, and does not require protection to install, unlike fiberglass insulation. Wool is a highly effective insulating material which performs better than its rated R value because it can absorb and release moisture. Mongolian nomads used felted and woven sheep