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,
Building insulation materials lightweight wood fiber, cellulose, seaweed, etc. Similarly, many plant-based waste materials can be used as insulation such as nut shells, the cob of corns, most straws including lavender straw, recycled wine bottle corks (granulated), etc. They may have a little less thermal performance than industrial products which can re-gained with a little more thickness. They may or may not require fire retardants or anti-insect/pest treatments. Clay coating is a nontoxic additive which often meets these requirements. Traditional clay-impregnated light straw insulation has been used for centuries in the northern climates of Europe. The clay coating gives the insulation a half