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 is important to ensure high energy efficiency. Loose-fill materials can be blown into attics, finished wall cavities, and hard-to-reach areas. They are ideal for these tasks because they conform to spaces and fill in the nooks and crannies. They can also be sprayed in place, usually with water-based adhesives. Many types are made of recycled materials (a type of cellulose) and are relatively inexpensive. General procedure for retrofits in walls: US regulatory standards for cellulose insulation Skylights, solariums and other special applications may use aerogels, a high-performance, low-density material. Silica aerogel has the lowest thermal conductivity of any known substance