Type X

• Type X drywall comes in 1/2 and 5/8 inch thicknesses and is fire resistant. This type of firewall has a mixture of gypsum, glass fiber, perlite, vermiculite and boric acid to increase its fire resistance. The glass fiber and gypsum also make the board moisture and mold resistant.
  
  

Type C

• Available in 1/2 and 5/8 inch thicknesses, Type C drywall has greater resistance to moisture, fire, abuse and mold. It comes with a gypsum core and a thick cover of fiberglass and other fire-resistant materials. Gypsum is a supple whitish-gray substance made up of hydrated calcium sulfate.
  
  

Fiberglass Drywall

• Fiberglass drywall also has a core made of gypsum and has fiberglass covering both sides of the board. This type of drywall has become common in basements because it has moisture-, mold- and fire-resistant properties. Both the gypsum core and fiberglass coating do not allow water to permeate, and they burn slowly, preventing fire hazards in the basement.
  
  

Cement Drywall

• Often used as backing for tiles in bathrooms and kitchens, cement board also makes a good drywall for basements. This type of drywall consists of cement sheets coated on both sides by a fiberglass mesh. Cement board has moisture-, mold- and fire-resistant properties. The fiberglass coating does not allow moisture to reach the cement core and does not burn easily. The cement core is strong and can tolerate abuse when the basement is used for purposes other than storage.
  
  

Foil-backed Drywall

• Foil-backed drywall has a gypsum core and an aluminum foil backing. Aluminum foil is used to make fireproof jackets and has good moisture resistance. Mold does not easily grow on foil. This type of drywall makes a good wall base for basements due to the fire and moisture resistance.