The roof covering that consists of individual overlapping elements are called roof shingles. The elements feature usually of flat and rectangular shapes that are laid in courses from the bottom edge of the roof going up, and each course overlaps the joints below in successive method. You will find shingles in different materials, from wood, slate, flagstone, metal, plastic, and composite materials like fibre cement and asphalt shingles. In Europe and some parts in Asia, the ceramic roof tiles, usually just called tiles, are in dominance in use.
Because roof shingles are the most visible aspect of a building, its patterns, textures and colors are very important features that contribute to the aesthetics of the building. Generally, the materials of roof shingles, just like the other materials on vernacular buildings, are available locally. Before construction commences, the kind of shingle is taken into consideration especially because its material would affect the roof pitch and the method of construction. The installation of some shingles are on lath while others would need solid sheathing on the deck of the roof. To avoid leaks, all shingle roofs are installed from the bottom going up, and it begins with a starter course with the edge seams offset. Especially in cold climates when snow, ice dams, wind and rain would occur, it would benefit shingle installations to be placed on top of an underlayment material such as asphalt felt paper to prevent leaks. Note that one feature that would influence the use of roof shingles are its fire rating, where some are rated non-combustible over the others, thus building codes do not allow the use of less class-A fire rating of shingles on some kinds of buildings. Compared to the fiberglass-based asphalt shingles, wood shingles and organic-based asphalt shingles are less commonly used due to its fire hazard possibility. The minimum recommended roof pitch of shingles is 4:12 with no underlayment material under it since shingles are not water-tight.
Fiberglass-based asphalt shingles are by far the most common roofing used for the applications in residential roofing like in the country of the United States. The much less common are the bitumen roof shingles or tile strips, which are used in Europe, are easy to install, relatively affordable, and could last 20 to 50 years.
As you choose your roof shingles, be aware of its protective nature, such as the long-chain petroleum carbons that protect the nature of paper and fiberglass asphalt shingles, and the natural oils in the cellulose structure of the wood shingles.
You will find other types of shingles made of different materials, and so you have stone shingles, fiber cement shingles, metal shingles, plastic shingles and cedar shingles.