Who makes rock wool in America?

In the United States, several companies manufacture rock wool, also known as mineral wool or stone wool. Notable producers include Roxul, a subsidiary of the multinational company Rockwool International, and CertainTeed, a brand of Saint-Gobain. Other manufacturers include Thermafiber and Johns Manville, both of which offer various insulation products, including rock wool. These companies supply rock wool for insulation, soundproofing, and fire-resistant applications across various industries.