Building insulation materials is used depends on a wide variety of factors. Some insulation materials have health risks, some so significant the materials are no longer allowed to be used but remain in use in some older buildings such as asbestos fibers and urea. Factors affecting the type and amount of insulation to use in a building include: Considerations regarding building and climate: Often a combination of materials is used to achieve an optimum solution and there are products which combine different types of insulation into a single form. Spray foam is a type of insulation that is sprayed in place through a
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