GAF is is a roofing manufacturing business that was started in 1886 in Parsippany, New Jersey. Enjoying the position of North America's largest manufacturer of commercial and residential roofing products, GAF boasts of sales approaching $3 billion. Timberline HD, the standard line of lifetime shingles by GAF is the #1 selling line in the country. GAF offers the highest standard of warranties and roofing certifications, owing to its superior product quality and reliability in the industry. GAF provides its Master Elite™ Certification to the best contractors in the roofing industry.