Calcium silicate bonded with sodium silicate. Although it is popularly considered an asbestos substitute, early uses of calcium silicate for insulation still made use of asbestos fibers. It is used in passive fire protection and fireproofing as calcium silicate brick or in roof tiles. It is one of the most successful materials in fireproofing in Europe because of regulations and fire safety guidelines for commercial and residential building codes (see Calcium Silicate use in Europe). Where North Americans use spray fireproofing plasters, Europeans are more likely to use cladding made of calcium silicate. High-performance calcium-silicate boards retain their excellent dimensional stability even
Cellulose insulation a building from damage in a fire better than fiberglass because cellulose is denser and restricts the oxygen necessary to burn structural members. Several National Research Council Canada studies have backed these claims. Another major reason for the comeback of cellulose might be because of the increased interest in green building. Cellulose has the highest recycled content of any insulation material and also has less embodied energy than fiberglass and other furnace-produced mineral insulation. Cellulose insulation is often made by hammer milling waste newspaper. The newspaper is treated with chemicals, such as boric acid, to retard the spread of fire.