Drywall, also called plasterboard, wallboard or gypsum board, can be recycled into new products to reduce waste and improve the condition of soil. Recycling drywall saves money for builders and homeowners, and helps reduce the amount of waste dumped into landfills. The practice has also created new business opportunities for companies that convert new or used drywall into usable materials.
The most common material used on interior walls of buildings is drywall, which is gypsum covered with paper and paperboard. If the paper is removed, wallboard can be recycled into new drywall. The paper, which acts as a fire retardant, inhibits the amount of gypsum in recycled drywall. Studies are being done to reduce the amount of paper on building materials to create more efficient drywall recycling options.
Some recycled drywall is used to amend soils in agriculture, nurseries, and recreation areas. Only new drywall is recommended for this purpose because used wallboard often contains paint and other chemicals that might be harmful to the environment. It is estimated that about 12 percent of drywall used is wasted as scrap, mostly from new construction projects. Demolition, manufacturing, and home renovation make up smaller percentages of drywall waste.
The gypsum contained in this building material is a naturally occurring mineral taken from arid sea beds. When products containing gypsum are added to alkali soil, it improves water penetration and neutralizes acid content. Some plants benefit from the calcium and sulfuric properties of gypsum. The gypsum can also be sold to specific cement plants that use this mineral in their manufacturing processes.
Boron is added to drywall as a fire retardant. If boron content of soil is low, recycled drywall can improve the condition. This is especially true in soils that contain volcanic ash that depletes boron. Too much boron in the soil can kill some species of plants, so its content should be checked before recycled wallboard is added to the earth.
Drywall recycling is done by separating gypsum from the paper added to wallboard. The main concern from the process is dust. Drywall recycling equipment generally includes a system for collecting dust and screening the materials. Water is often used to reduce the amount of dust generated during drywall recycling. In some areas, an air quality permit is needed before the process can be carried out.