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
Aluminium silicate Aluminium silicate Aluminium silicate (or aluminum silicate) is a name commonly applied to chemical compounds which are derived from aluminium oxide, AlO and silicon dioxide, SiO which may be anhydrous or hydrated, naturally occurring as minerals or synthetic. Their chemical formulae are often expressed as xAlO.ySiO.zHO. It is known as E number E559. Aluminium silicate is a type of fibrous material made of aluminium oxide and silicon dioxide, (such materials are also called aluminosilicate fibres). These are glassy solid solutions rather than chemical compounds. The compositions are often described in terms of % weight of alumina, AlO and silica, SiO.