Also cement board provides a stronger bond and support with tiles than typical gypsum board. The walls consist of gypsum board and plaster. CNBM is currently the largest cement and gypsum board producer in China. A typical US home contains 7 metric tons of such drywall gypsum board. It is approximately twice that of gypsum board, making handling by one person difficult. Most were of a semi-permanent type, using gypsum board. All these, except gypsum board, contain cellulose, which is transformable into cellulosic ethanol. Adhesives are commonly used to attach EIFS to gypsum board, cement board, or concrete substrates. In drywall (gypsum board), calcium formate can function as a fire retardant.