List of commercially available roofing material
Roofing material is the outermost layer on the roof of a building, sometimes self supporting, but generally supported by an underlying structure. A building's roofing material provides shelter from the natural elements, and insulation against heat and cold. The outer layer of a roof shows great variation dependent upon availability of material, and the nature of the supporting structure. Those types of roofing material which are commercially available range from natural products such as thatch and slate to commercially produced products such as tiles and polycarbonate sheeting.
Commercially available roofing materials
The weather proofing material is the topmost or outermost layer, exposed to the weather. Many materials have been used as weather proofing material:
- Thatch is roofing made of plant stalks in overlapping layers.[1]
- Wheat Straw, widely used in England, France and other parts of Europe.
- Seagrass, used in coastal areas where there are estuaries such as Scotland. Has a longer life than straw. Claimed to have a life in exccess of 60 years.[2]
- Rye Straw, commonly used in Eastern Europe.
- Shingles, also called shakes in North America. Shingles is the generic term for a roofing material that is in many overlapping sections, regardless of the nature of the material. The word is also used specifically to denote shingles made of wood.
- Slate. High cost with a life expectancy of up to 200 years.[5] Slate cleaves into thin sheets, making it much lighter than concrete tiles, though heavier than sheet steel and other light roof coverings.
- Stone slab. Heavy stone slabs (not to be confused with slate) 1"-2" thick were formerly used as roofing tiles in some regions in England, the Alps, and Scandinavia. Stone slabs require a very heavyweight roof structure, but their weight makes them stormproof. An obsolete roofing material, now used commercially only for building restoration.
- Ceramic tile. High cost, life of more than 100 years.[6]
- Imbrex and tegula, style dating back to ancient Greece and Rome.
- Monk and Nun, a style similar to Imbrex and tegula, but basically using two Imbrex tiles.
- Metal shakes or shingles. Long life. High cost, suitable for roofs of 3/12 pitch or greater. Because of the flexibility of metal, they can be manufactured to lock together, giving durability and reducing assembly time.[7]
- Mechanically seamed metal. Long life. High cost, suitable for roofs of low pitch such as 0.5/12 to 3/12 pitch.
- Concrete, usually reinforced with fibres of some sort. Concrete tiles require a stronger roof structure than slate, as some owners have found to their cost.
- Asphalt shingle, made of bitumen embedded in an organic or fiberglass mat, usually covered with colored, man-made ceramic grit. Cheaper than slate or tiles. Various life span expectancies.
- Asbestos shingles. Very long lifespan, fireproof and low cost but now rarely used because of health concerns.[8][9]
- Membrane Roofing. Membrane roofing is in large sheets, generally fused in some way at the joints to form a continuous surface.
- Thermoset membrane (e.g. EPDM rubber). Synthetic rubber sheets adhered together with contact adhesive or tape. Primary application is big box store with large open areas.
- Thermoplastic (e.g. PVC, TPO, CSPE). Plastic sheets welded together with hot air creating one continuous sheet membrane. Can be rewelded with the exception of CSPE. Lends itself well to both big box and small roof application because of its hot air weldability. This membrane is installed by two methods: 1.) Rolls of membrane are attached to the ridged insulation using a bonding adhesive. 2.) The edge of each roll is fastened through ridged insulation into structural deck, and the proceeding roll is lapped over the fasteners. The overlap is then heat-welded with hot air to create a mechanically-fastened thermoplastic roof.
- Modified bitumen - heat welded, asphalt adhered or installed with adhesive. Asphalt is mixed with polymers such as APP or SBS, then applied to fiberglass and/or polyester mat, seams sealed by locally melting the asphalt with heat, hot mopping of asphalt, or adhesive. Lends itself well to most applications.
- Built-Up Roof - Multiple plies of salt saturated organic felt or coated fiberglass felts. Plies of felt are adhered with hot asphalt, coal tar pitch or adhesive. Although the roof membrane can be left bare, it is typically covered with a thick coat of the water-proofing material and covered with gravel. The gravel provides protection from ultra-violet degradation, stabilizes the temperature changes, protects surface of the roof and increases the weight of the roof system to resist wind blow-off.
- Fabric
- Metal roofing. Generally a relatively inexpensive building material, unless copper is used.
- Galvanised steel frequently manufactured with wavy corrugations to resist lateral flexing and fitted with exposed fasteners. Widely used for low cost and durability. Sheds are normally roofed with this material. Known as Gal iron or Corro, it was the most extensively used roofing material of 20th century Australia, now replaced in popularity by steel roofing coated with an alloy of zinc and aluminium, claimed to have up to four times the life of galvanized steel.[10]
- Standing-seam metal with concealed fasteners.
- Mechanically seamed metal with concealed fasteners contains sealant in seams for use on very low sloped roofs.
- Flat-seam metal with soldered seams.
Gallery of commercial roofing materials
See also
References