VALLEY FORGE, Pa. - This year, CertainTeed Corp., a North American manufacturer of building materials, including HVAC products, becomes one of the few companies to have reached 100 years in business.

CertainTeed is one of the nation's largest manufacturers of roofing, siding, windows, insulation, fencing, decking, railing, foundations and PVC pipe products.

Founded by George Brown in 1904, CertainTeed got its start in East St. Louis, Ill., as the General Roofing Manufacturing Co. A decade later, the company slogan "Quality Made Certain, Satisfaction Guaranteed" became the inspiration for the CertainTeed name.

"We are proud to be among the enduring companies that have had the acumen to thrive through a century's worth of evolving business climates," said Jean-François Phelizon, president of CertainTeed. "Our 100-year history is testament to CertainTeed's expert understanding of the building industry and succession of smart business decisions as well as the commitment and dedication of our 7,000 employees throughout the United States."

In 1988, CertainTeed became a division of Saint-Gobain Corp., the $6 billion French building materials giant.