Owens Corning makes and sells building products for residential and commercial markets, primarily in North America and Europe, across three segments: Roofing, Insulation, and Doors. Roofing (~43% of revenue) is the largest segment, producing laminate asphalt shingles and complementary roofing components. Owens Corning is the second-largest U.S. asphalt shingle producer and is vertically integrated into glass nonwoven mats and asphalt processing. Insulation (~36% of revenue) makes fiberglass batts, loosefill, spray foam, and XPS foam board under brands including FOAMULAR and Paroc, sold into residential, commercial, and industrial end markets across North America and Europe. Doors (~21% of revenue) was added via the May 2024 acquisition of Masonite, and produces interior and exterior residential doors in wood, fiberglass, and metal. Owens Corning sells primarily through distributors, home centers, and contractors; in Roofing, contractor brand loyalty is central to its go-to-market approach. Over half of revenue comes from repair and remodeling activity, with nondiscretionary reroofing a key driver in Roofing. Margins in Roofing are driven by the spread between asphalt/glass fiber input costs and selling prices, and are bolstered by storm-driven demand. Insulation margins are more sensitive to industry capacity utilization. Doors is being restructured post-acquisition, targeting $125M in cost synergies and $75M in network savings to reach 20%+ EBITDA margins. Owens Corning is also investing in capacity expansions in Roofing and Insulation, and is divesting its glass reinforcements business for ~$474M.