Ashlar ( / ˈ æ ʃ l ər / ) is a cut and dressed stone , worked using a chisel to achieve a specific form, typically rectangular in shape. The term can also refer to a structure built from such stones.
84-530: Ashlar is the finest stone masonry unit, and is generally rectangular ( cuboid ). It was described by Vitruvius as opus isodomum or trapezoidal . Precisely cut "on all faces adjacent to those of other stones", ashlar is capable of requiring only very thin joints between blocks, and the visible face of the stone may be quarry-faced or feature a variety of treatments: tooled, smoothly polished or rendered with another material for decorative effect. One such decorative treatment consists of small grooves achieved by
168-407: A CMU wall having much greater lateral and tensile strength than unreinforced walls. "Architectural masonry is the evolvement of standard concrete masonry blocks into aesthetically pleasing concrete masonry units (CMUs)". CMUs can be manufactured to provide a variety of surface appearances. They can be colored during manufacturing or stained or painted after installation. They can be split as part of
252-427: A base coat is applied with a common mix of 4 parts sand to one part cement and one part dehydrated lime and water to make a consistent mortar. Render is applied using a hawk and trowel and pushed on about 12 mm thick to begin. For two coat, some plasterers apply two full depth bands of render (one at the base of the wall and one around chest height) which are screeded plumb and square and allowed to dry while applying
336-498: A base, to which a certain proportion of another substance, such as alum , borax or carbonate of soda , is added, and the whole baked or calcined at a low temperature. The plaster they contain causes them to set quickly with a very hard smooth surface, which may be painted or papered within a few hours of its being finished. In Australia , plaster or cement render that is applied to external brickwork on dwellings or commercial buildings can be one or two coats. In two coat render
420-418: A coat of well-haired coarse stuff composed either of good hydraulic lime or of Portland cement. This layer is well scratched to give a key for the next coat. The second coat is also composed of coarse stuff knocked up to a smooth and uniform consistency. Two finish two techniques can be used: Sgraffito is the name for scratched ornament in plaster. Scratched ornament is the oldest form of surface decoration, and
504-427: A darker color or an irregular shape. Others may use antique salvage bricks, or new bricks may be artificially aged by applying various surface treatments, such as tumbling. The attempts at rusticity of the late 20th century have been carried forward by masons specializing in a free, artistic style, where the courses are intentionally not straight, instead weaving to form more organic impressions. A crinkle-crankle wall
588-406: A fine mist spray to dampen walls when rubbing up (using a wood float to bring a consistent finish). Using a hose brings a superior finish and is more consistent in colour as there is more chance in catching the render before it has a chance to harden too much. After the work area is floated, the surface is finished with a wet sponge using the same method as floating with a wood float, bringing sand to
672-455: A half ( 1 ⁄ 4 in or 6.4 mm thick), and double ( 3 ⁄ 8 – 1 ⁄ 2 in or 9.5–12.7 mm thick). The thicker laths should be used in ceilings, to stand the extra strain (sometimes they were doubled for extra strength), and the thinner variety in vertical work such as partitions, except where the latter will be subjected to rough usage, in which case thicker laths become necessary. Laths are usually nailed with
756-488: A hand float on the surface of the rendering, which must first be well wetted. Stucco is a term loosely applied to nearly all kinds of external plastering, whether composed of lime or of cement. At the present time it has fallen into disfavor, but in the early part of the 19th century a great deal of this work was done. Cement has largely superseded lime for this work. The principal varieties of stucco are common, rough, trowelled and bastard. . Roughcast or pebbledash plastering
840-826: A joining material such as mortar to bind the blocks together, although dry ashlar construction, metal ties, and other methods of assembly have been used. The dry ashlar of Inca architecture in Cusco and Machu Picchu is particularly fine and famous. The word is attested in Middle English and derives from the Old French aisselier , from the Latin axilla , a diminutive of axis , meaning "plank". "Clene hewen ashler" often occurs in medieval documents; this means tooled or finely worked, in contradistinction to rough-axed faces. In tile carpet installation "ashlar" refers to
924-401: A joist or stud. All timbers over 3 inches (76 mm) wide should be counter-lathed, that is, have a fillet or double lath nailed along the centre upon which the laths are then nailed. This is done to preserve a good key for the plaster. Walls liable to damp are sometimes battened and lathed to form an air cavity between the damp wall and the plastering. Lathing in metal, either in wire or in
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#17327835471731008-421: A layer of plaster on an interior or exterior wall structure, or plaster decorative moldings on ceilings or walls. This is also sometimes called pargeting . The process of creating plasterwork, called plastering or rendering , has been used in building construction for centuries. For the art history of three-dimensional plaster, see stucco . The earliest plasters known to us were lime-based. Around 7500 BC,
1092-518: A layer of sponge or expanded polystyrene. Traditionally, plaster was laid onto laths, rather than plasterboard as is more commonplace nowadays. Wooden laths are narrow strips of straight-grained wood depending on availability of species in lengths of from two to four or five feet to suit the distances at which the timbers of a floor or partition are set. Laths are about an inch wide, and are made in three thicknesses; single ( 1 ⁄ 8 to 3 ⁄ 16 in or 3.2 to 4.8 mm thick), lath and
1176-575: A masonry wall is not entirely dependent on the bond between the building material and the mortar; the friction between the interlocking blocks of masonry is often strong enough to provide a great deal of strength on its own. The blocks sometimes have grooves or other surface features added to enhance this interlocking, and some dry set masonry structures forgo mortar altogether. Stone blocks used in masonry can be dressed or rough, though in both examples corners, door and window jambs, and similar areas are usually dressed. Stonemasonry utilizing dressed stones
1260-508: A non-staggered bond. The wide selection of brick styles and types generally available in industrialized nations allow much variety in the appearance of the final product. In buildings built during the 1950s-1970s, a high degree of uniformity of brick and accuracy in masonry was typical. In the period since then this style was thought to be too sterile, so attempts were made to emulate older, rougher work. Some brick surfaces are made to look particularly rustic by including burnt bricks, which have
1344-408: A permanent colored facing (typically composed of polyester resins, silica sand and various other chemicals) to a concrete masonry unit, providing a smooth impervious surface." Glass block or glass brick are blocks made from glass and provide a translucent to clear vision through the block. A masonry veneer wall consists of masonry units, usually clay-based bricks, installed on one or both sides of
1428-456: A product he introduced in 1818. In 1822, in the UK, James Frost patented (another?) process, similar to Vicat's, producing what he called "British cement". Portland cement, patented in 1824 by Joseph Aspdin , was called so because it was supposed to resemble Portland stone. Aspdinís son William, and later Isaac Johnson, improved the production process. A product, very similar to modern Portland cement,
1512-410: A space of about 3 ⁄ 8 inch (9.5 mm) between them to form a key for the plaster. Laths were formerly all made by hand. Most are now made by machinery and are known as sawn laths, those made by hand being called rent or riven laths. Rent laths give the best results, as they split in a line with the grain of the wood, and are stronger and not so liable to twist as machine-made laths, some of
1596-404: A sponge, the second coat is left rough and sometimes will be scored by nails inserted in the float. After drying, the surface is then scraped to remove loose grains of sand before plastering. If the walls are concrete, a splash coat is needed to ensure bonding. A splash coat is a very wet mix of two parts cement to one part sand that is "splashed" on the wall using the plasterers brush until the wall
1680-431: A structurally independent wall usually constructed of wood or masonry. In this context, the brick masonry is primarily decorative, not structural. The brick veneer is generally connected to the structural wall by brick ties (metal strips that are attached to the structural wall, as well as the mortar joints of the brick veneer). There is typically an air gap between the brick veneer and the structural wall. As clay-based brick
1764-497: A variety of cements , and various ingredients to form color washes . While most tools have remained unchanged over the centuries, developments in modern materials have led to some changes. Trowels, originally constructed from steel, are now available in a polycarbonate material that allows the application of certain new, acrylic-based materials without staining the finish. Floats, traditionally made of timber (ideally straight-grained, knot-free, yellow pine), are often finished with
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#17327835471731848-416: A veneer and became a more integral part of the building structure. Early 19th century rendered façades were colour-washed with distemper ; oil paint for external walls was introduced around 1840. The 19th century also saw the revival of the use of oil mastics. In the UK, patents were obtained for "compositions" in 1803 (Thomas Fulchner), 1815 (Christopher Dihl) and 1817 (Peter Hamelin). These oil mastics, as
1932-427: A vertical 1/2 offset pattern. Ashlar blocks have been used in the construction of many buildings as an alternative to brick or other materials. In classical architecture , ashlar wall surfaces were often contrasted with rustication . The term is frequently used to describe the dressed stone work of prehistoric Greece and Crete , although the dressed blocks are usually much larger than modern ashlar. For example,
2016-516: A very large boxwood mould collection. In 1774, in France, a mémoire was published on the composition of ancient mortars. This was translated into English as "A Practical Essay on a Cement, and Artificial Stone, justly supposed to be that of the Greeks and Romans" and was published in the same year. Following this, and as a backlash to the disappointment felt due to the repeated failure of oil mastics, in
2100-478: A wall of a given size. Furthermore, cinder and concrete blocks typically have much lower water absorption rates than brick. They often are used as the structural core for veneered brick masonry or are used alone for the walls of factories, garages, and other industrial-style buildings where such appearance is acceptable or desirable. Such blocks often receive a stucco surface for decoration. Surface-bonding cement , which contains synthetic fibers for reinforcement,
2184-558: Is a brick wall that follows a serpentine path, rather than a straight line. This type of wall is more resistant to toppling than a straight wall; so much so that it may be made of a single wythe of unreinforced brick and so despite its longer length may be more economical than a straight wall. Blocks of cinder concrete ( cinder blocks or breezeblocks ), ordinary concrete ( concrete blocks ), or hollow tile are generically known as Concrete Masonry Units (CMUs). They usually are much larger than ordinary bricks and so are much faster to lay for
2268-400: Is a rough form of external plastering in much use for country houses. In Scotland it is termed " harling ". It is one of the oldest forms of external plastering. In Tudor times it was employed to fill in between the woodwork of half-timbered framing. When well executed with good material this kind of plastering is very durable. Roughcasting is performed by first rendering the wall or laths with
2352-410: Is applied to about 5 mm thick and when the render hardens is screeded off straight. A wood float or plastic float is used to rub down the walls. Traditionally, water is splashed on walls using a coarse horsehair plasterers brush followed by immediately rubbing the float in a circular or figure 8 motion although a figure of 8 can leave marks. Many modern plasterers use a hose with a special nozzle with
2436-403: Is composed of lime, sand, hair and water in proportions varying according to the nature of the work to be done. The lime mortar principally used for internal plastering is that calcined from chalk , oyster shells or other nearly pure limestone , and is known as fat, pure, chalk or rich lime. Hydraulic limes are also used by the plasterer, but chiefly for external work. Perfect slaking of
2520-420: Is generally a highly durable form of construction. However, the materials used, the quality of the mortar and workmanship, and the pattern in which the units are assembled can substantially affect the durability of the overall masonry construction. A person who constructs masonry is called a mason or bricklayer . These are both classified as construction trades . Masonry is one of the oldest building crafts in
2604-416: Is generally used where quality of finish is at a premium. The second method is quicker but can be several millimetres out of plumb. The second coat can be a slightly weaker mix 5/1/1, or the same as the base coat with maybe a water- proofer in the mix added to the water to minimize efflorescence (rising of salts). Some plasterers used lime putty in second coat instead of dehydrated lime in the render. The mortar
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2688-456: Is known as ashlar masonry, whereas masonry using irregularly shaped stones is known as rubble masonry . Both rubble and ashlar masonry can be laid in coursed rows of even height through the careful selection or cutting of stones, but a great deal of stone masonry is uncoursed. Solid brickwork is made of two or more wythes of bricks with the units running horizontally (called stretcher bricks) bound together with bricks running transverse to
2772-488: Is much used on the continent of Europe, especially in Germany and Italy, in both external and internal situations. Properly treated, the work is durable, effective and inexpensive. A first coat or rendering of Portland cement and sand, in the proportion of one to three, is laid on about an inch thick; then follows the color coat, sometimes put on in patches of different tints as required for the finished design. When this coat
2856-423: Is nearly dry, it is finished with a smooth-skimming, 1 ⁄ 12 to 1 ⁄ 8 inch (2.1 to 3.2 mm) thick, of Parian, selenitic or other fine cement or lime, only as much as can be finished in one day being laid on. Then by pouncing through the pricked cartoon, the design is transferred to the plastered surface. Broad spaces of background are now exposed by removing the finishing coat, thus revealing
2940-442: Is not so strong as ox-hair. The quantity used in good work is one pound of hair to two or three cubic feet of coarse stuff (in the UK up to 12 kg per metric cube). Hair reinforcement in lime plaster is common and many types of hair and other organic fibres can be found in historic plasters [4]. However, organic material in lime will degrade in damp environments particularly on damp external renders.[5] This problem has given rise to
3024-549: Is only as long as the wire they are composed of and if used in severe climates (such as shore-side in a salt water environment) must be made of appropriate corrosion-resistant wire. Most modern gabions are rectangular. Earlier gabions were often cylindrical wicker baskets, open at both ends, used usually for temporary, often military, construction. Similar work can be done with finer aggregates using cellular confinement . Masonry walls have an endothermic effect of its hydrates , as in chemically bound water , unbound moisture from
3108-426: Is sometimes substituted or mixed with the ox-hair in the lower qualities. Good hair should be long (In the UK cow and horse hair of short and long lengths is used), and left greasey (lanolin grease) because this protects against some degradation when introduced into the very high alkaline plaster. Before use it must be well beaten, or teased, to separate the lumps. In America, goats ' hair is frequently used, though it
3192-717: Is sometimes used in this application and can impart extra strength to a block wall. Surface-bonding cement is often pre-colored and can be stained or painted thus resulting in a finished stucco-like surface. The primary structural advantage of concrete blocks in comparison to smaller clay-based bricks is that a CMU wall can be reinforced by filling the block voids with concrete with or without steel rebar . Generally, certain voids are designated for filling and reinforcement, particularly at corners, wall-ends, and openings while other voids are left empty. This increases wall strength and stability more economically than filling and reinforcing all voids. Typically, structures made of CMUs will have
3276-458: Is the best material on account of its strength, durability, and weather resisting external properties, but not on historic structures that are required to flex and breathe; for this, lime without cement is used. Sawdust has been used as a substitute for hair and also instead of sand as an aggregate . Sawdust will enable mortar to stand the effects of frost and rough weather. It is useful sometimes for heavy cornices and similar work, as it renders
3360-496: Is usually not completely waterproof, the structural wall will often have a water-resistant surface (usually tar paper ) and weep holes can be left at the base of the brick veneer to drain moisture that accumulates inside the air gap. Concrete blocks, real and cultured stones , and veneer adobe are sometimes used in a very similar veneer fashion. Most insulated buildings that use concrete block, brick, adobe, stone, veneers or some combination thereof feature interior insulation in
3444-456: The tholos tombs of Bronze Age Mycenae use ashlar masonry in the construction of the so-called "beehive" dome. This dome consists of finely cut ashlar blocks that decrease in size and terminate in a central capstone . These domes are not true domes, but are constructed using the corbel arch . Ashlar masonry was also heavily used in the construction of palace facades on Crete , including Knossos and Phaistos . These constructions date to
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3528-463: The MM III-LM Ib period, c. 1700 –1450 BC. In modern European masonry the blocks are generally about 35 centimetres (14 in) in height. When shorter than 30 centimetres (12 in), they are usually called small ashlar . In some Masonic groupings, which such societies term jurisdictions , ashlars are used as a symbolic metaphor for how one's personal development relates to
3612-471: The 16th century, a new highly decorative type of decorative internal plasterwork, called scagliola , was invented by stuccoists working in Bavaria. This was composed of gypsum plaster, animal glue and pigments, used to imitate coloured marbles and pietre dure ornament. Sand or marble dust, and lime, were sometimes added. In this same century, the sgraffito technique, also known as graffito or scratchwork
3696-452: The 1820s. The popularisation of Portland cement changed the composition of stucco, as well as mortar , to a harder material. The development of artificial cements had started early in the 19th century. In 1811, James Frost took out a patent for an artificial cement obtained by lightly calcining ground chalk and clay together. The French Engineer Louis Vicat in 1812–1813 experimented with calcining synthetic mixtures of limestone and clay,
3780-451: The 19th century, various mixtures of modified gypsum plasters, such as Keene's cement, appeared. These materials were developed for use as internal wall plasters, increasing the usefulness of simple plaster of Paris as they set more slowly and were thus easier to use. Tools and materials include trowels , floats, hammers , screeds, hawk , scratching tools, utility knives , laths , lath nails , lime , sand , hair , plaster of Paris ,
3864-678: The Freemason who, through education and diligence, has learned the lessons of Freemasonry and who lives an upstanding life. Masonry Masonry is the craft of building a structure with brick, stone, or similar material, including mortar plastering which are often laid in, bound, and pasted together by mortar . The term masonry can also refer to the building units (stone, brick, etc.) themselves. The common materials of masonry construction are bricks and building stone , rocks such as marble , granite , and limestone , cast stone , concrete blocks , glass blocks , and adobe . Masonry
3948-672: The Roman period until the 18th century. Plaster decoration was widely used in Europe in the Middle Ages where, from the mid-13th century, gypsum plaster was used for internal and external plaster. Hair was employed as reinforcement, with additives to assist set or plasticity including malt, urine, beer, milk and eggs. In the 14th century, decorative plasterwork called pargeting was being used in South-East England to decorate
4032-611: The UK in this period included a "Composition or stone paste" patented in 1765 by David Wark. This was a lime-based mix and included "oyls of tar, turpentine and linseed" besides many other ingredients. Another "Composition or cement", including drying oil, was patented in 1773 by Rev. John Liardet. A similar product was patented in 1777 by John Johnson. Widely used by the architect Robert Adam who in turn commissioned George Jackson to produce reverse-cut boxwood moulds (many of which to Adam designs). Jackson formed an independent company which still today produces composition pressings and retains
4116-773: The application of a metal comb. Generally used only on softer stone ashlar, this decoration is known as "mason's drag". Ashlar is in contrast to rubble masonry , which employs irregularly shaped stones, sometimes minimally worked or selected for similar size, or both. Ashlar is related but distinct from other stone masonry that is finely dressed but not quadrilateral, such as curvilinear and polygonal masonry . Ashlar may be coursed , which involves lengthy horizontal layers of stone blocks laid in parallel, and therefore with continuous horizontal joints. Ashlar may also be random, which involves stone blocks laid with deliberately discontinuous courses and therefore discontinuous joints both vertically and horizontally. In either case, it generally uses
4200-472: The best limes were those fired from limestones containing a considerable quantity of clay]ey material. In 1796, Revd James Parker patented Parker's " Roman Cement ". This was a hydraulic cement which, when mixed with sand, could be used for stucco. It could also be cast to form mouldings and other ornaments. It was however of an unattractive brown colour, which needed to be disguised by surface finishes. Natural cements were frequently used in stucco mixes during
4284-419: The calcined lime before being used is very important as, if used in a partially slaked condition, it will "blow" when in position and blister the work. Lime should therefore be run as soon as the building is begun, and at least three weeks should elapse between the operation of running the lime and its use. Hair is used in plaster as a binding medium, and gives tenacity to the material. Traditionally horsehair
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#17327835471734368-651: The colored plaster beneath, and following this the outlines of the rest of the design are scratched with an iron knife through the outer skimming to the underlying tinted surface. Sometimes the coats are in three different colors, such as brown for the first, red for the second, and white or grey for the final coat. The pigments used for this work include Indian red, Turkey red, Antwerp blue, German blue, umber, ochre, purple brown, bone black or oxide of manganese for black. Combinations of these colors are made to produce any desired tone. Plasters are applied in successive coats or layers on walls or lathing and gains its name from
4452-534: The concrete block, and the poured concrete if the hollow cores inside the blocks are filled. Masonry can withstand temperatures up to 1,000 °F (538 °C) and it can withstand direct exposure to fire for up to 4 hours. In addition to that, concrete masonry keeps fires contained to their room of origin 93% of the time. For those reasons, concrete and masonry units hold the highest flame spread index classification, Class A. Fire cuts can be used to increase safety and reduce fire damage to masonry buildings. From
4536-648: The cores remain unfilled. Filling some or all of the cores with concrete or concrete with steel reinforcement (typically rebar ) offers much greater tensile and lateral strength to structures. One problem with masonry walls is that they rely mainly on their weight to keep them in place; each block or brick is only loosely connected to the next via a thin layer of mortar. This is why they do not perform well in earthquakes, when entire buildings are shaken horizontally. Many collapses during earthquakes occur in buildings that have load-bearing masonry walls. Besides, heavier buildings having masonry suffer more damage. The strength of
4620-442: The exterior of timber-framed buildings. This is a form of incised, moulded or modelled ornament, executed in lime putty or mixtures of lime and gypsum plaster. During this same period, terracotta was reintroduced into Europe and was widely used for the production of ornament. In the mid-15th century, Venetian skilled workers developed a new type of external facing, called marmorino made by applying lime directly onto masonry. In
4704-399: The fibers of which are usually cut in the process of sawing. Laths must be nailed so as to break joint in bays three or four feet wide with ends butted one against the other. By breaking the joints of the lathing in this way, the tendency for the plaster to crack along the line of joints is diminished and a better key is obtained. Every lath should be nailed at each end and wherever it crosses
4788-494: The finished surface was often painted or decorated. Modelled stucco was employed throughout the Roman Empire. The Romans used mixtures of lime and sand to build up preparatory layers over which finer applications of gypsum , lime, sand and marble dust were made; pozzolanic materials were sometimes added to produce a more rapid set. Following the fall of the Roman Empire, the addition of marble dust to plaster to allow
4872-409: The first coat over the remaining exposed wall. The render is then scratched to provide a key for the second coat. This method allows the rest of the wall to be rendered and screeded off without the need to continually check if the second coat is plumb. Alternatively, both coats can be applied with the plasterer using a t-bar to screed the final coat until it is plumb, straight and square. The first method
4956-411: The form of fiberglass batts between wooden wall studs or in the form of rigid insulation boards covered with plaster or drywall . In most climates this insulation is much more effective on the exterior of the wall, allowing the building interior to take advantage of the aforementioned thermal mass of the masonry. This technique does, however, require some sort of weather-resistant exterior surface over
5040-757: The form of perforated galvanised sheets, is now extensively used on account of its fireproof and lasting quality. There are many kinds of this material in different designs, the best known in England being the Jhilmil, the Bostwick, Lathing, and Expanded Metal lathing. The two last-named are also widely used in the United States. Lathing nails are usually of iron, cut, wrought or cast, and in the better class of work they are galvanized to prevent rusting. Zinc nails are sometimes used, but are costly. Lime plastering
5124-511: The hemp fiber being undamaged. For fine plasterer's sand-work, special sands are used, such as silver sand, which is used when a light color and fine texture are required. In the United Kingdom this fine white sand is procured chiefly from Leighton Buzzard; also in the UK many traditional plasters had crushed chalk as the aggregate, this made a very flexible plaster suitable for timber-frame buildings. For external work Portland cement
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#17327835471735208-464: The insulation and, consequently, is generally more expensive. Gabions are baskets, usually now of zinc -protected steel ( galvanized steel ) that are filled with fractured stone of medium size. These will act as a single unit and are stacked with setbacks to form a revetment or retaining wall . They have the advantage of being well drained, flexible, and resistant to flood, water flow from above, frost damage, and soil flow. Their expected useful life
5292-457: The manufacturing process, giving the blocks a rough face replicating the appearance of natural stone, such as brownstone . CMUs may also be scored, ribbed, sandblasted, polished, striated (raked or brushed), include decorative aggregates, be allowed to slump in a controlled fashion during curing, or include several of these techniques in their manufacture to provide a decorative appearance. "Glazed concrete masonry units are manufactured by bonding
5376-413: The material light and strong. The sawdust should be used dry. The sawdust is used to bind the mix sometimes to make it go further. The first coat or rendering is from 1 ⁄ 2 to 3 ⁄ 4 inches thick, and is mixed in the proportions of from one part of cement to two of sand to one part to five of sand. The finishing or setting coat is about 3 ⁄ 16 inches thick, and is worked with
5460-413: The number of these coats. The process for three coat work is as follows: The composition of an interior three coat plaster: The hard cements used for plastering, such as Parian, Keene's, and Martin's, are laid generally in two coats, the first of cement and sand 1/2 to 3/4 inches thick, the second or setting coat of neat cement about 1/8 inch thick. These and similar cements have gypsum as
5544-418: The ones before them, also proved to be short-lived. Moulded or cast masonry substitutes, such as cast stone and poured concrete , became popular in place of quarried stone during the 19th century. However, this was not the first time "artificial stone" had been widely used. Coade Stone , a brand name for a cast stone made from fired clay, had been developed and manufactured in England from 1769 to 1843 and
5628-601: The people of 'Ain Ghazal in Jordan used lime mixed with unheated crushed limestone to make plaster which was used on a large scale for covering walls, floors, and hearths in their houses. Often, walls and floors were decorated with red, finger-painted patterns and designs. In ancient India and China, renders in clay and gypsum plasters were used to produce a smooth surface over rough stone or mud brick walls, while in early Egyptian tombs, walls were coated with lime and gypsum plaster and
5712-401: The point of view of material modeling, masonry is a special material of extreme mechanical properties (with a very high ratio between strength in compression and in tension), so that the applied loads do not diffuse as they do in elastic bodies, but tend to percolate along lines of high stiffness. Plastering Plasterwork is construction or ornamentation done with plaster , such as
5796-525: The production of fine detail and a hard, smooth finish in hand-modelled and moulded decoration was not used until the Renaissance. Around the 4th century BC, the Romans discovered the principles of the hydraulic set of lime, which by the addition of highly reactive forms of silica and alumina, such as volcanic earths , could solidify rapidly even under water. There was little use of hydraulic mortar after
5880-477: The render doesn't bond completely with the wall, either because the wall is too smooth, a coat is too thick, or the coat is being floated when the render has hardened too much, leaving an air space that makes a drumming sound when a metal tool is "rubbed" over it. For internal walls, two coats is the standard and follows the same method as for external rendering but with a weaker mix of five or six sand to one cement and one lime. However, instead of being finished with
5964-409: The second half of the 18th century water-based renders gained popularity once more. Mixes for renders were patented, including a "Water Cement, or Stucco" consisting of lime, sand, bone ash and lime-water (Dr Bryan Higgins, 1779). Various experiments mixing different limes with volcanic earths took place in the 18th century. John Smeaton (from 1756) experimented with hydraulic limes and concluded that
6048-469: The surface to give a smooth consistent finish. Materials used in the render are commonly local sands with little clay content with fine to coarse grains. Sand finish is common for external render and may be one or two coats. Plasterers use a t-bar to screed the walls until it is plumb, straight and square. Two coat is superior as, although more expensive, it gives a more consistent finish and has less chance of becoming drummy or cracking. Drumminess occurs when
6132-552: The tenets of their lodge . As described in the explanation of the First Degree Tracing Board , in Emulation and other Masonic rituals the rough ashlar is a stone as taken directly from the quarry, and allegorically represents the Freemason prior to his initiation; a smooth ashlar (or "perfect ashlar") is a stone that has been smoothed and dressed by the experienced stonemason , and allegorically represents
6216-730: The tension force present in modern thin, light, tall building systems. Masonry has both structural and non-structural applications. Structural applications include walls, columns, beams, foundations, load-bearing arches, and others. On the other hand, masonry is also used in non-structural applications such as fireplaces chimneys and veneer systems. Brick and concrete block are the most common types of masonry in use in industrialized nations and may be either load-bearing or non-load-bearing. Concrete blocks, especially those with hollow cores, offer various possibilities in masonry construction. They generally provide great compressive strength and are best suited to structures with light transverse loading when
6300-410: The top course of blocks in the walls filled with concrete and tied together with steel reinforcement to form a bond beam. Bond beams are often a requirement of modern building codes and controls. Another type of steel reinforcement referred to as ladder-reinforcement , can also be embedded in horizontal mortar joints of concrete block walls. The introduction of steel reinforcement generally results in
6384-504: The use of polyprolene fibres and cellulose wood fibres in new lime renders [6] Manila hemp fiber has been used as a substitute for hair. Plaster for hair slabs made with manila hemp fiber broke at 195 lb (88 kg), plaster mixed with sisal hemp at 150 lb (68 kg), jute at 145 lb (66 kg), and goats' hair at 144 lb (65 kg). Another test was made in the following manner. Two barrels of mortar were made up of equal proportions of lime and sand, one containing
6468-466: The usual quantity of goats' hair, and the other Manila fiber. After remaining in a dry cellar for nine months the barrels were opened. It was found that the hair had been almost entirely eaten away by the action of the lime, and the mortar consequently broke up and crumbled quite easily. The mortar containing the Manila hemp, on the other hand, showed great cohesion, and required some effort to pull it apart,
6552-597: The wall (called "header" bricks). Each row of bricks is known as a course. The pattern of headers and stretchers employed gives rise to different 'bonds' such as the common bond (with every sixth course composed of headers), the English bond, and the Flemish bond (with alternating stretcher and header bricks present on every course). Bonds can differ in strength and in insulating ability. Vertically staggered bonds tend to be somewhat stronger and less prone to major cracking than
6636-413: The world. The construction of Egyptian pyramids, Roman aqueducts, and medieval cathedrals are all examples of masonry. Early structures used the weight of the masonry itself to stabilize the structure against lateral movements. The types and techniques of masonry used evolved with architectural needs and cultural norms. Since mid-20th century, masonry has often featured steel-reinforced elements to help carry
6720-428: Was an artificial marble made using gypsum (sometimes with lime), pigments, water and glue. Stucco lustro was another a form of imitation marble (sometimes called stucco lucido) where a thin layer of lime or gypsum plaster was applied over a scored support of lime, with pigments scattered on surface of the wet plaster. The 18th century gave rise to renewed interest in innovative external plasters. Oil mastics introduced in
6804-456: Was available from about 1845, with other improvements taking place in the following years. Thus, after about 1860, most stucco was composed primarily of Portland cement, mixed with some lime. This made it even more versatile and durable. No longer used just as a coating for a substantial material like masonry or log, stucco could now be applied over wood or metal lath attached to a light wood frame. With this increased strength, it ceased to be just
6888-463: Was introduced into Germany by Italian artists, combining it with modelled stucco decoration. This technique was practised in antiquity and was described by Vasari as being a quick and durable method for decorating building facades. Here, layers of contrasting lime plaster were applied and a design scratched through the upper layer to reveal the colour beneath. The 17th century saw the introduction of different types of internal plasterwork. Stucco marble
6972-405: Was the most commonly used binder, as it was easily available before the development of the motor-car. Hair functions in much the same way as the strands in fiberglass resin, by controlling and containing any small cracks within the mortar while it dries or when it is subject to flexing. Ox -hair, which is sold in three qualities, is now the kind usually specified; but horsehair, which is shorter,
7056-547: Was used for decorative architectural elements. Following the closure of the factory in South London, Coade stone stopped being produced, and the formula was lost. By the mid 19th century manufacturing centres were preparing cast stones based on cement for use in buildings. These were made primarily with a cement mix often incorporating fine and coarse aggregates for texture, pigments or dyes to imitate colouring and veining of natural stones, as well as other additives. Also in
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