Granules (3a6de1a4-02b8-454b-adab-e7d7b80b6b54)

Granules are used primarily as roofing material. From the earliest times, man has been faced with the basic problem of providing protection for himself, his family, and his property against the ravages of the weather. Basically, this problem is no different today than in the past, except that today the trend is to demand shelter which is also colorful and distinctive. There has been a gradual evolution from the thatched roof to the modem ranchstyle home. In his search for a more permanent and more attractive roof, the home owner has utilized many mineral materials. All granules, whether slate or colored granules, are referred to by the asphalt roofing industry as "Slate Granules." Early Roofing Materials The development of mineral roofing in the United States followed two trends: first, the slate industry, and second, the bituminous products. The early colonists were familiar with slab slate construction from Europe and it was natural for them to continue with this type of roofing. As early as 1780, the forerunners of the present bituminous products were finding favor. Those early products consisted of saturating burlap or similar material with crude tar or pitch. This type of roofing was soon improved by dusting a variety of materials on the surface of the roofing to prevent adhesion while in rolls. Such factors as fire resistance and protection from the actinic rays of the sun soon followed. This started the general pattern which is still followed today, that is, saturating felt materials and supplying a uniform grade of crushed mineral to the surface. In commercial and public buildings, metal roofs found early favor. The attractive green color of verdigris-coated copper became a symbol of churches and institutions of learning. Aluminum roofing has become economical for large structures and is finding limited popularity in rural areas. Tile, asbestos, and cement materials, being weather resistant, found early acclaim and are still popular. Today, by far the most widely used roofing materials in the United States are asphalt products. Two important characteristics-economy and weatherability-account for their popularity. Influence of Building Trends on Roofing The postwar building boom in 1947 had many attractive features for the American people. The ranch-style one story type of home seemed well suited for suburban developments which sprang up in such profusion. As the roof in modern home construction is one of the most conspicuous aspects of its architecture, the home owner could now express his tastes not only in paint and landscaping, but could also select an attractive and harmonious roof color. Variety of Minerals Used Many naturally occurring minerals are used today in the roofing industry. Most widely used (and most noticeable to the public) is the granulated mineral surfacing applied to asphalt products. Selected natural colored granules as well as artificially colored granules are