CertainTeed Corp. joins the ranks of the companies to have reached 100 years of service. The manufacturers of roofing, siding, windows, insulation, fencing, decking, railing, foundations and PVC pipe products was founded by George Brown in 1904. The company began in East St. Louis, Ill., as the General Roofing Manufacturing Co.

CertainTeed entered the fiberglass insulation business in 1964 when it purchased an insulation plant in Mountaintop, Pa., from the Pall Corp. Two years later, CertainTeed purchased the Gustin-Bacon Manufacturing Co., Kansas City, Kan., and, in 1973 entered the duct liner business when its plant in Corbin, Ky., started production.

"We are proud to be among the enduring companies that have had the acumen to thrive through the nation's evolving business climates over the years," said Jorma Toivonen, president of CertainTeed's Insulation Group.