|
Roofing Construction
Domestic roof construction is the framing and roof covering which is found on most detached houses in cold and temperate climates. Such roofs are built with mostly timber, take a number of different shapes, and are covered with a variety of materials. Overview Modern timber roofs are mostly framed with pairs of common rafters or prefabricated wooden trusses fastened together with truss connector plates. Timber framed and historic buildings may be framed with principal rafters or timber roof trusses. Roofs are also designated as ''warm'' or ''cold roof'' depending on how they are designed and built with regard to thermal building insulation and ventilation. The steepness or roof pitch of a sloped roof is determined primarily by the roof covering material and aesthetic design. Flat roofs actually slope up to approximately ten degrees to shed water. Flat roofs on houses are primarily found in arid regions. In high wind areas, such as where a cyclone or hurricane may make landfal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Imperial Units
The imperial system of units, imperial system or imperial units (also known as British Imperial or Exchequer Standards of 1826) is the system of units first defined in the British Weights and Measures Act 1824 and continued to be developed through a series of Weights and Measures Acts and amendments. The imperial system developed from earlier English units as did the related but differing system of customary units of the United States. The imperial units replaced the Winchester Standards, which were in effect from 1588 to 1825. The system came into official use across the British Empire in 1826. By the late 20th century, most nations of the former empire had officially adopted the metric system as their main system of measurement, but imperial units are still used alongside metric units in the United Kingdom and in some other parts of the former empire, notably Canada. The modern UK legislation defining the imperial system of units is given in the Weights and Measures Act ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collar Beam
A collar beam or collar is a horizontal member between two rafters and is very common in domestic roof construction. Often a collar is structural but they may be used simply to frame a ceiling. A collar beam is often called a collar tie but this is rarely correct. A tie in building construction is an element in tension rather than compression and most collar beams are designed to work in compression to keep the rafters from sagging. A collar near the bottom of the rafters may replace a tie beam and be designed to keep the rafters from spreading, thus are in tension: these are correctly called a collar tie. Etymology ''Collar'' in general comes from Latin ''collare'' meaning neck. Collar beam roofs The simplest form of roof framing is a common rafter roof. This roof framing has nothing but rafters and a tie beam at the bottoms of the rafters. The next step in the development of roof framing was to add a collar, called a collar beam roof. Collar beam roofs are suitable for spans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tie (engineering)
A tie, strap, tie rod, eyebar, guy-wire, suspension cables, or wire ropes, are examples of linear structural components designed to resist tension. It is the opposite of a strut or column, which is designed to resist compression. Ties may be made of any tension resisting material. Application in wood construction In wood-frame construction ties are generally made of galvanized steel. Wood framing ties generally have holes allowing them to be fastened to the wood structure by nails or screws. The number and type of nails are specific to the tie and its use. The manufacturer generally specifies information as to the connection method for each of their products. Among the most common wood framing ties used is the hurricane tie or seismic tie used in the framing of wooden structures where wind uplift or seismic overturning is a concern. Hurricane tie A hurricane tie is used to help make a structure (specifically wooden structures) more resistant to high winds (such as in hurric ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oriented Strand Board
Oriented strand board (OSB) is a type of engineered wood similar to particle board, formed by adding adhesives and then compressing layers of wood strands (flakes) in specific orientations. It was invented by Armin Elmendorf in California in 1963. OSB may have a rough and variegated surface with the individual strips of around , lying unevenly across each other, and is produced in a variety of types and thicknesses. Uses OSB is a material with favorable mechanical properties that make it particularly suitable for load-bearing applications in construction. It is now more popular than plywood, commanding 66% of the North American structural panel market. The most common uses are as sheathing in walls, flooring, and roof decking. For exterior wall applications, panels are available with a radiant-barrier layer laminated to one side; this eases installation and increases energy performance of the building envelope. OSB is also used in furniture production. Manufacturing Oriente ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plywood
Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured boards which include medium-density fibreboard (MDF), oriented strand board (OSB) and particle board (chipboard). All plywoods bind resin and wood fibre sheets (cellulose cells are long, strong and thin) to form a composite material. This alternation of the grain is called ''cross-graining'' and has several important benefits: it reduces the tendency of wood to split when nailed at the edges; it reduces expansion and shrinkage, providing improved dimensional stability; and it makes the strength of the panel consistent across all directions. There is usually an odd number of plies, so that the sheet is balanced—this reduces warping. Because plywood is bonded with grains running against one another and with an odd number of composite part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purlin
A purlin (or historically purline, purloyne, purling, perling) is a longitudinal, horizontal, structural member in a roof. In traditional timber framing there are three basic types of purlin: purlin plate, principal purlin, and common purlin. Purlins also appear in steel frame construction. Steel purlins may be painted or greased for protection from the environment. Etymology Information on the origin of the term "purlin" is scant. The Oxford Dictionary suggests a French origin, with the earliest quote using a variation of ''purlin'' in 1447, though the accuracy of this claim has been disputed. In wood construction Purlin plate A purlin plate in wood construction is also called an "arcade plate" in European English, "under purlin", and "principal purlin". The term plate means a major, horizontal, supporting timber. Purlin plates are beams which support the mid-span of rafters and are supported by posts. By supporting the rafters they allow longer spans than the rafters alone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Batten
A batten is most commonly a strip of solid material, historically wood but can also be of plastic, metal, or fiberglass. Battens are variously used in construction, sailing, and other fields. In the lighting industry, battens refer to linear light fittings. In the steel industry, battens used as furring may also be referred to as "top hats", in reference to the profile of the metal. Roofing ''Roofing battens'' or ''battening'', also called ''roofing lath'', are used to provide the fixing point for roofing materials such as shingles or tiles. The spacing of the battens on the trusses or rafters depend on the type of roofing material and are applied horizontally like purlins. Battens are also used in metal roofing to secure the sheets called a ''batten-seam roof'' and are covered with a ''batten roll joint''. Some roofs may use a grid of battens in both directions, known as a ''counter-batten system'', which improves ventilation. Roofing battens are most commonly made of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lath
A lath or slat is a thin, narrow strip of straight-grained wood used under roof shingles or tiles, on lath and plaster walls and ceilings to hold plaster, and in lattice and trellis work. ''Lath'' has expanded to mean any type of backing material for plaster. This includes metal wire mesh or expanded metal that is applied to a wood or metal framework as matrix over which stucco or plaster is applied, as well as wallboard products called gypsum or rock lath.Ching, Frank. ''A visual dictionary of architecture''. New York: Van Nostrand Reinhold, 1995. 198. Print. Historically, reed mat was also used as a lath material. One of the key elements of lath, whether wooden slats or wire mesh, are the openings or gaps that allow plaster or stucco to ooze behind and form a mechanical bond to the lath. This is not necessary for gypsum lath, which relies on a chemical bond. Etymology The word is recorded from the late 13th century and is likely derived from the Old English word *, a var ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wall Plate
A plate or wall plate is a horizontal, structural, load-bearing member in wooden building framing. Timber framing A plate in timber framing is "A piece of Timber upon which some considerable weight is framed...Hence Ground-Plate...Window-plate bsolete.." etc. Also called a wall plate, raising plate,Sturgis, Russell. ''Sturgis' illustrated dictionary of architecture and building: an unabridged reprint of the 1901-2 edition''. 1901. Reprint. Mineola, N.Y.: Dover, 1989. 159. Print. or top plate,Sherwood, Gerald E., and Robert C. Stroh. ''Wood-frame house construction''. Washington, D.C.: U.S. Dept. of Agriculture, Forest Service :, 1989. 54. Print. An exception to the use of the term plate for a large, load-bearing timber in a wall is the bressummer, a timber supporting a wall over a wall opening (see also: lintel). These are common in Australia. The terms sole plate or sill plate are used for the members at the bottom of a wall at the foundation but are most often just called ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rafter
A rafter is one of a series of sloped structural members such as wooden beams that extend from the ridge or hip to the wall plate, downslope perimeter or eave, and that are designed to support the roof shingles, roof deck and its associated loads. A pair of rafters is called a ''couple''. In home construction, rafters are normally made of wood. Exposed rafters are a feature of some traditional roof styles. Applications In recent buildings there is a preference for trussed rafters on the grounds of cost, economy of materials, off-site manufacture, and ease of construction, as well as design considerations including span limitations and roof loads (weight from above). Types in traditional timber framing There are many names for rafters depending on their location, shape, or size (see below). The earliest surviving roofs in Europe are of common rafters on a tie beam; this assembly is known as a "closed couple". Later, principal rafters and common rafters were mixed, which is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flashing (weatherproofing)
Flashing refers to thin pieces of impervious material installed to prevent the passage of water into a structure from a joint or as part of a weather resistant barrier system. In modern buildings, flashing is intended to decrease water penetration at objects such as chimneys, vent pipes, walls, windows and door openings to make buildings more durable and to reduce indoor mold problems. Metal flashing materials include lead, aluminium, copper, stainless steel, zinc alloy, and other materials. Etymology and related terms The origin of the term ''flash'' and ''flashing'' are uncertain, but may come from the Middle English verb ''flasshen'', 'to sprinkle, splash', related to ''flask''. ''Counter-flashing'' (or ''cover flashing'', ''cap flashing'') is a term used when there are two parallel pieces of flashing employed together such as on a chimney, where the counter-flashing is built into the chimney and overlaps a replaceable piece of ''base flashing''. Strips of lead used for flash ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
