Westlake Royal Building Products™ Broadens Kleer® and TruExterior® Distribution Through Expanded BlueLinx Partnership

* Westlake Royal Building Products has broadened its distribution partnership with BlueLinx, with Westlake Royal becoming BlueLinx's sole PVC trim supplier, further expanding the long-standing relationship between the two companies. * Kleer(®) PVC Trim will be available through 27 BlueLinx distribution locations serving customers throughout New England, the North and Mid-Atlantic, the South, the Ohio Valley and select Central U.S. markets. * TruExterior(®) Siding & Trim distribution will expand from 12 to 17 BlueLinx locations, including five additional locations in Massachusetts, Vermont, Maine and New York. * The expanded relationship reinforces both companies' commitment to helping building professionals and homeowners access durable, low-maintenance siding and trim solutions through one of North America's largest building products distribution networks. HOUSTON, Sept. 24, 2026 (GLOBE NEWSWIRE) -- Westlake Royal Building Products(™) (“Westlake Royal”), a Westlake company (NYSE: WLK), today announced an expanded distribution agreement with BlueLinx, one of North America's leading building products distributors. Through the long-standing partnership, Westlake Royal will serve as BlueLinx’s sole PVC trim supplier, distributing Kleer(®) PVC Trim across its network while also broadening the geographic footprint of TruExterior(®) Siding & Trim.