Johns Manville Receives UL Certification for DuraCore® 300

Johns Manville (JM), a Berkshire Hathaway Company and a market-leading manufacturer of glass fiber products, received UL certification for DuraCore® 300 chopped strands used to reinforce wallboards in the building industry. The product is manufactured at JM’s facility in Slovakia.

This certification confirms that JM’s DuraCore® product line continues to meet the most stringent quality standards in the market. JM places tremendous importance on supporting the Global Gypsum industry and continues to develop best-in-class glass fibers.

“Our customers can continuously rely on UL certified DuraCore® products with improved dosing consistency and dispersion in wallboards,” said Jared Cox, Global Product Manager-Chopped Strands Fibers for JM Engineered Products. 

About Johns Manville
Johns Manville, a Berkshire Hathaway company (NYSE: BRK.A, BRK.B), is a leading manufacturer and marketer of premium-quality products for building insulation, mechanical insulation, commercial roofing, and roof insulation, as well as fibers and nonwovens for commercial, industrial and residential applications. JM serves markets that include aerospace, automotive and transportation, air handling, appliance, HVAC, pipe and equipment, filtration, waterproofing, building, flooring, interiors and wind energy. In business since 1858, the Denver-based company has annual sales of approximately $2.6 billion and holds leadership positions in all of the key markets that it serves. JM employs approximately 7,000 people and operates 44 manufacturing facilities in North America, Europe and China. Additional information can be found at

About UL
UL is a global independent safety science company with more than a century of expertise innovating safety solutions from the public adoption of electricity to new breakthroughs in sustainability, renewable energy and nanotechnology. Dedicated to promoting safe living and working environments, UL helps safeguard people, products and places in important ways, facilitating trade and providing peace of mind. Additional information can be found at

Philippe Bekaert +32 479 980 677