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| | The weather proofing material is the topmost or outermost layer, exposed to the weather. Many different kinds of materials have been used as weather proofing material: - Thatch is roofing made of plant stalks in overlapping layers.
- Wheat Straw, widely used in England, France and other parts of Europe.
- Seagrass, used in coastal areas where there are esturies such as Scotland. Has a longer life than straw. Claimed to have a life in exccess of 60 years
- Shingles, 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. Slate cleaves into thin sheets, making it much lighter than concrete tiles, though heavier than sheet steel and other light roofcoverings.
- 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. Stone slabs require a very heavyweight roof structure, but their weight makes them stormproof. An obsolete roofing material.
- Ceramic tile. High cost, life of more then 100 years.
- 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.
- 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.
- Membrane. 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.
- 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 asphalt saturated organic felt or coated fiberglass felts. Plies of felt are adhered with hot asphalt, coal tar pitch or adhesive.
- Sprayed-in-Place Polyurethane Foam (SPUF) - Foam sprayed in-place on the roof, then coated with a wide variety of coatings, or in some instances, covered with gravel.
- 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.
- 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.
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