Titulo

DRYWALL
1. INTRODUCTION TO WARM AND DRYWALL
This chapter describes the methodology used in EPA’s Waste Reduction Model (WARM) to estimate streamlined life‐cycle greenhouse gas (GHG) emission factors for drywall beginning at the waste generation reference point. 1 The WARM GHG emission factors are used to compare the net emissions associated with drywall in the following three waste management alternatives: source reduction, recycling and landfilling. Exhibit 1 shows the general outline of materials management pathways for drywall in WARM. For background information on the general purpose and function of WARM emission factors, see the Introduction & Overview chapter. For more information on Source Reduction, Recycling and Landfilling, see the chapters devoted to those processes. WARM also allows users to calculate results in terms of energy, rather than GHGs. The energy results are calculated using the same methodology described here but with slight adjustments, as explained in the Energy Impacts chapter.
Exhibit 1: Life Cycle of Drywall in WARM
Raw Material & Intermediate Product Acquisition, Processing, & Transport (Virgin Manufacture Only) Raw Material Acquisition, Processing, & Transport (Virgin Manufacture Only)

Transport to Retail Facility

Drywall Manufacture: Recycling Offsets Virgin Manufacture

19% of recycled drywall to closed loop recycling

Transport to Manufacturing or Packaging Facility

81% of recycled drywall to open loop recycling

Agric. Gypsum Production: Recycling Offsets Virgin Manufacture

Transport to Farm

Product Use Product Use
WARM Starts Here

Drywall
Only Scrap from Construction Sites

Recycling

Collection/Transport to Recycling Facility

Recycled Drywall Grinding & Paper Screening

Composting

Not Modeled
Life‐Cycle Stages That Are GHG Sources (Positive Emissions) Life‐Cycle Stages That Result in Both Positive and Negative Emissions Steps Not