CertainTeed Corporationcelebrated its 100th year of service this month. A longtime leader in innovation and creative product design within the building products industry, CertainTeed now joins the ranks of the few proud companies to have reached 100 years of service. One hundred years ago this month, George M. Brown founded General Roofing Company in East St. Louis, IL with just $25,000. The company's commitment to service and high-quality materials were well represented by the slogan, "Quality Made Certain, Satisfaction Guaranteed," which grew into a byword of employees and customers, soon becoming the inspiration for the lasting CertainTeed name.