Existing Gypsum Drywall
From Green Garage Detroit
- Facts about Gypsum Drywall 
- Reuse Ideas
- Existing Drywall can be salvaged and reused in new wall applications in the building.
- Use as thermal mass. Dry wall has a fairly high specific heat capacity, which makes it a good candidate for thermal mass. One consideration is putting the old drywall under the new drywall for additional thermal mass for the external walls.
- Use the gypsum as material for stucco / plaster after removing the paper backing. After removing the paper from dry wall even more uses for the gypsum become available, such as adding the gypsum to stucco or plaster, using it as a soil amendment or chalk lines for sports fields.
- Local Recycling
http://1greenamerica.com/ Offers recycling options for building materials including drywall.