Masonry is the building of structures from individual units laid in and bound together by
mortarMortar is a workable paste used to bind construction blocks together and fill the gaps between them. The blocks may be stone, brick, cinder blocks, etc. Mortar becomes hard when it sets, resulting in a rigid aggregate structure. Modern mortars are typically made from a mixture of sand, a binder...
; the term
masonry can also refer to the units themselves. The common materials of masonry construction are
brickA brick is a block of ceramic material used in masonry construction, usually laid using various kinds of mortar. It has been regarded as one of the longest lasting and strongest building materials used throughout history.-History:...
,
stoneIn geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
,
marbleMarble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite.Geologists use the term "marble" to refer to metamorphosed limestone; however stonemasons use the term more broadly to encompass unmetamorphosed limestone.Marble is commonly used for...
,
graniteGranite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
,
travertineTravertine is a form of limestone deposited by mineral springs, especially hot springs. Travertine often has a fibrous or concentric appearance and exists in white, tan, and cream-colored varieties. It is formed by a process of rapid precipitation of calcium carbonate, often at the mouth of a hot...
,
limestoneLimestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
; concrete block,
glassGlass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...
block,
stuccoStucco or render is a material made of an aggregate, a binder, and water. Stucco is applied wet and hardens to a very dense solid. It is used as decorative coating for walls and ceilings and as a sculptural and artistic material in architecture...
, and
tileA tile is a manufactured piece of hard-wearing material such as ceramic, stone, metal, or even glass. Tiles are generally used for covering roofs, floors, walls, showers, or other objects such as tabletops...
. Masonry 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 significantly affect the durability of the overall masonry construction.
Masonry units, such as brick, tile, stone, glass brick or concrete block generally conform to the requirements specified in the 2003
International Building CodeThe International Building Code is a model building code developed by the International Code Council . It has been adopted throughout most of the United States.-History:...
(
IBCIBC is an initialism that can stand for:*IBC Root Beer*Impedance Boundary Condition*Independence Blue Cross*Índice Bursátil Caracas, a stock market index of the Caracas Stock Exchange*Inflammatory Breast Cancer*Institute of Business Consulting...
) Section 2103.
Applications
Masonry is commonly used for the walls of buildings, retaining walls and monuments. Brick and concrete block are the most common types of masonry in use in industrialized nations and may be either weight-bearing or a veneer. 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 the cores remain unfilled. Filling some or all of the cores with concrete or concrete with steel reinforcement (typically
rebarA rebar , also known as reinforcing steel, reinforcement steel, rerod, or a deformed bar, is a common steel bar, and is commonly used as a tensioning device in reinforced concrete and reinforced masonry structures holding the concrete in compression...
) offers much greater tensile and lateral strength to structures.
Advantages
- The use of materials such as brick and stone can increase the thermal mass of a building.
- Brick typically will not require painting and so can provide a structure with reduced life-cycle costs.
- Masonry is very heat resistant and thus provides good fire protection.
- Masonry walls are more resistant to projectiles, such as debris from hurricanes or tornadoes.
- Masonry structures built in compression preferably with lime mortar can have a useful life of more than 500 years as compared to 30 to 100 for structures of steel or reinforced concrete.
Disadvantages
- Extreme weather causes degradation of masonry wall surfaces due to frost damage.
- This type of damage is common with certain types of brick, though rare with concrete blocks.
- Masonry tends to be heavy and must be built upon a strong foundation, such as reinforced concrete, to avoid settling and cracking.
- Not suitable for habitat in tropical climate having heavy heat and rain conditions
Structural limitations
Masonry boasts an impressive compressive strength (vertical loads) but is much lower in tensile strength (twisting or stretching) unless reinforced. The tensile strength of masonry walls can be strengthened by thickening the wall, or by building masonry
piers (vertical columns or ribs) at intervals. Where practical, steel reinforcements can be added.
Veneer masonry
A masonry veneer wall consists of masonry units, usually clay-based bricks, installed on one or both sides of 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 is usually not completely waterproof, the structural wall will often have a water-resistant surface (usually
tar paperTar paper is a heavy-duty paper used in construction. Tar paper is made by impregnating paper with tar, producing a waterproof material useful for roof construction. It can be distinguished from Roofing felt:Asphalt-saturated felt. Roofing felt has been in use for over a hundred years...
) and
weep holeWeep holes or "weeper holes" are small openings left in the outer wall of masonry construction as an outlet for water inside a building to move outside the wall and evaporate. The term was coined by archaeologist C. Leonard Woolley after finding evidence of weep holes in ziggurats...
s 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 utilize concrete block, brick, adobe, stone, veneers or some combination thereof feature interior
insulationThermal insulation is the reduction of the effects of the various processes of heat transfer between objects in thermal contact or in range of radiative influence. Heat transfer is the transfer of thermal energy between objects of differing temperature...
in the form of
fiberglassGlass wool or fiberglass insulation is an insulating material made from fiberglass, arranged into a texture similar to wool. Glass wool is produced in rolls or in slabs, with different thermal and mechanical properties....
batts between wooden wall studs or in the form of rigid insulation boards covered with
plasterPlaster is a building material used for coating walls and ceilings. Plaster starts as a dry powder similar to mortar or cement and like those materials it is mixed with water to form a paste which liberates heat and then hardens. Unlike mortar and cement, plaster remains quite soft after setting,...
or
drywallDrywall, also known as plasterboard, wallboard or gypsum board is a panel made of gypsum plaster pressed between two thick sheets of paper...
. 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 the insulation and, consequently, is generally more expensive.
Dry set masonry
The strength of a masonry wall is not entirely dependent on the bond between the building material and the mortar; the
frictionFriction is the force resisting the relative motion of solid surfaces, fluid layers, and/or material elements sliding against each other. There are several types of 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.
Solid masonry
Solid masonry, without steel reinforcement, tends to have very limited applications in modern wall construction. While such walls can be quite economical and suitable in some applications. Solid
unreinforced masonryAn Unreinforced masonry building is a type of building where load bearing walls, non-load bearing walls or other structures, such as chimneys are made of brick, cinderblock, tiles, adobe or other masonry material, that is not braced by reinforcing beams...
walls tend to be low and thick as a consequence.
Brick
Solid
brickworkBrickwork is masonry produced by a bricklayer, using bricks and mortar to build up brick structures such as walls. Brickwork is also used to finish corners, door, and window openings, etc...
is made of two or more layers of bricks with the units running horizontally (called
stretcher bricks) bound together with bricks running
transverseIn mathematics, transversality is a notion that describes how spaces can intersect; transversality can be seen as the "opposite" of tangency, and plays a role in general position. It formalizes the idea of a generic intersection in differential topology...
to 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 a non-staggered bond.
Uniformity and rusticity
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 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.
Serpentine masonry
A crinkle-crackle wall 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 thickness of unreinforced brick and so despite its longer length may be more economical than a straight wall.
Concrete block
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 a wall of a given size. Furthermore, cinder and concrete blocks typically have much lower
waterWater is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
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-styleIndustrial Style refers to an aesthetic trend in design that emphasizes sharp lines, abrupt connections and dynamic interactions of motion. It is derivative of the same forces that created the architectural movement Deconstructivism and the anime genre Mecha, and can be seen in such automobile...
buildings where such appearance is acceptable or desirable. Such blocks often receive a
stuccoStucco or render is a material made of an aggregate, a binder, and water. Stucco is applied wet and hardens to a very dense solid. It is used as decorative coating for walls and ceilings and as a sculptural and artistic material in architecture...
surface for decoration. Surface-bonding
cementIn the most general sense of the word, a cement is a binder, a substance that sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term opus caementicium to describe masonry resembling modern concrete that was made from crushed...
, which contains synthetic fibers for reinforcement, is sometimes used in this application and can impart extra strength to a block wall. Surface-bonding cement is often pre-coloured 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
concreteConcrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
with or without steel
rebarA rebar , also known as reinforcing steel, reinforcement steel, rerod, or a deformed bar, is a common steel bar, and is commonly used as a tensioning device in reinforced concrete and reinforced masonry structures holding the concrete in compression...
. 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 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 codeA building code, or building control, is a set of rules that specify the minimum acceptable level of safety for constructed objects such as buildings and nonbuilding structures. The main purpose of building codes are to protect public health, safety and general welfare as they relate to the...
s 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 a CMU wall having much greater lateral and tensile strength than unreinforced walls.
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 the manufacturing process, giving the blocks a rough face replicating the appearance of natural stone, such as
brownstoneBrownstone is a brown Triassic or Jurassic sandstone which was once a popular building material. The term is also used in the United States to refer to a terraced house clad in this material.-Types:-Apostle Island 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 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-Jacks
A-jackA-Jacks are a commercially made concrete product used in both open channel and coastal applications. They consist of two concrete T-shaped pieces joined perpendicularly at the middle, forming six legs...
s (used in erosion control walls and sea walls) are highly stable, concrete 6-pronged armor units designed to interlock into a flexible, highly permeable matrix. They can be installed either randomly or in a uniform pattern. They look like giant 3-foot versions of the metal jacks that children play with.
In the uniform placement pattern, each unit is in contact with the six adjacent units, providing high stability. They are patterned after the buckyball model.
Stonework
- Stone blocks used in masonry can be dressed or rough.
- Stone masonry utilizing dressed stones is known as ashlar
Ashlar is prepared stone work of any type of stone. Masonry using such stones laid in parallel courses is known as ashlar masonry, whereas masonry using irregularly shaped stones is known as rubble masonry. Ashlar blocks are rectangular cuboid blocks that are masonry sculpted to have square edges...
masonry, whereas masonry using irregularly shaped stones is known as rubble masonryRubble masonry is rough, unhewn building stone set in mortar, but not laid in regular courses. It may appear as the outer surface of a wall or may fill the core of a wall which is faced with unit masonry such as brick or cut stone....
. Both rubble and ashlar masonry can be laid in courses rows of even height through the careful selection or cutting of stones, but a great deal of stone masonry is uncoursed.
- Slipform stonemasonry produces a hybrid wall of reinforced concrete with a rubble stone face.
- Natural stone veneers over CMU, cast-in-place, or tilt-up concrete walls are widely used to give the appearance of stone masonry.
- Sometimes river rock smooth oval-shaped stones is used as a veneer.
- This type of material is not favored for solid masonry as it requires a great amount of mortar and can lack intrinsic structural strength.
- Manufactured-stone, or cultured stone, veneers are popular alternatives to natural stones.
- Attractive natural stone has become more expensive in many areas and in some areas is practically unavailable.
- Manufactured-stone veneers are typically made from concrete.
- Natural stones from quarries around the world are sampled and recreated using molds, aggregate, and colorfast pigments.
- To the casual observer there may be no visual difference between veneers of natural and manufactured stone.
Gabions
GabionGabions are cages, cylinders, or boxes filled with soil or sand that are used in civil engineering, road building, and military applications. For erosion control caged riprap is used. For dams or foundation construction, cylindrical metal structures are used...
s are rectangular wire baskets, usually of
zincZinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
-protected
steelSteel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
(
galvanized steelHot-dip galvanizing is a form of galvanization. It is the process of coating iron, steel, or aluminum with a thin zinc layer, by passing the metal through a molten bath of zinc at a temperature of around 860 °F...
) 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 wallRetaining walls are built in order to hold back earth which would otherwise move downwards. Their purpose is to stabilize slopes and provide useful areas at different elevations, e.g...
. They have the advantage of being both well drained and flexible, and so resistant to flood, water flow from above, frost damage, and soil flow. Their expected useful life 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.
Bagged concrete
A low grade concrete may be placed in woven plastic sacks similar to that used for
sandbagA sandbag is a sack made of hessian/burlap, polypropylene or other materials that is filled with sand or soil and used for such purposes as flood control, military fortification, shielding glass windows in war zones and ballast....
s and then emplaced. The sacks are then watered and the emplacement then becomes a series of artificial stones that conform to one another and to adjacent soil and structures. This conformation makes them resistant to displacement. The sack becomes non-functional and eventually disintegrates. This type of masonry is frequently used to protect the entrances and exits of water conduits where a road passes over a stream or dry wash. It is also used to protect stream banks from erosion, especially where a road passes close by.
Masonry training
Stonemasonry is one of the oldest
professionA profession is a vocation founded upon specialized educational training, the purpose of which is to supply disinterested counsel and service to others, for a direct and definite compensation, wholly apart from expectation of other business gain....
s in the
history of constructionPeople have constructed buildings and other structures since prehistory, including bridges, amphitheatres, dams, electricity pylons, roads and canals. Building materials in present use have a long history and some of the structures built thousands of years ago can still be regarded as remarkable....
. As such it is regarded as a traditional skill, and is one which is in heavy demand.
Prospective stonemasons will learn the profession through apprenticeships or a traineeship that will last 3 to 4 years. There are City & Guilds stonemasonry courses available that combine college based
theoryThe English word theory was derived from a technical term in Ancient Greek philosophy. The word theoria, , meant "a looking at, viewing, beholding", and referring to contemplation or speculation, as opposed to action...
trainingThe term training refers to the acquisition of knowledge, skills, and competencies as a result of the teaching of vocational or practical skills and knowledge that relate to specific useful competencies. It forms the core of apprenticeships and provides the backbone of content at institutes of...
with practical learning.
Passive fire protection (PFP)
Masonry walls have an
endothermicIn thermodynamics, the word endothermic describes a process or reaction in which the system absorbs energy from the surroundings in the form of heat. Its etymology stems from the prefix endo- and the Greek word thermasi,...
effect of its
hydrateHydrate is a term used in inorganic chemistry and organic chemistry to indicate that a substance contains water. The chemical state of the water varies widely between hydrates, some of which were so labeled before their chemical structure was understood....
s, as in chemically bound
waterWater is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
, as well as unbound moisture from the concrete block, as well as the poured concrete if the hollow cores inside the blocks are filled.
Mechanical modelling of masonry structures
From the point of view of material modelling, 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 , see the figure on the right and watch a
video for more details.
See also
- Mason Contractors Association of America
The Mason Contractors Association of America is an organization in the United States of America that helps mason contractors.The Mason Contractors Association of America has a full time staff in Washington, D.C. representing the interests of MCAA members...
- Brick tinting
Brick tinting is the process of physically tinting bricks to either change the color or blend-in offending areas of brickwork with the surrounding masonry.-References:...
- Cast stone
Cast stone is defined as “a refined architectural concrete building unit manufactured to simulate natural cut stone, used in unit masonry applications”. In the UK and Europe cast stone is defined as “any material manufactured with aggregate and cementitious binder, intended to resemble in...
- Castle
A castle is a type of fortified structure built in Europe and the Middle East during the Middle Ages by European nobility. Scholars debate the scope of the word castle, but usually consider it to be the private fortified residence of a lord or noble...
- TC 125
CEN/TC 125 is a workgroup within the European Union working on standardization in the field of Masonry, including natural stone, in the European Union.-External links:*...
(European Union)
- Defensive wall
A defensive wall is a fortification used to protect a city or settlement from potential aggressors. In ancient to modern times, they were used to enclose settlements...
- Dry-stone wall
- Fire protection
Fire protection is the study and practice of mitigating the unwanted effects of fires. It involves the study of the behaviour, compartmentalisation, suppression and investigation of fire and its related emergencies, as well as the research and development, production, testing and application of...
- International Union of Bricklayers and Allied Craftworkers
The International Union of Bricklayers and Allied Craftworkers is a labor union in the United States and Canada which represents bricklayers, pointers/cleaners/caulkers, stone and marble masons, cement masons, plasterers, tilesetters, terrazzo and mosaic workers...
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List of stone
Operative Plasterers' and Cement Masons' International AssociationThe Operative Plasterers' and Cement Masons' International Association of the United States and Canada is a trade union of plasterers and cement masons in the construction industry in the United States and Canada. Members of the union finish interior walls and ceilings of buildings and apply...
Concrete finisherA concrete finisher, also known as a cement mason, is a tradesman who works with concrete. The job entails placing, finishing, protecting and repairing concrete in engineering and construction projects. Concrete finishers are often responsible for setting the concrete forms, ensuring they have the...
NIST stone test wallThe NIST stone test wall is an experiment by the United States National Institute of Standards and Technology to determine how different types of construction stone weather. It includes 2352 samples of stone from 47 different states within the US and 16 different countries...
Passive fire protectionPassive fire protection is an integral component of the three components of structural fire protection and fire safety in a building. PFP attempts to contain fires or slow the spread, through use of fire-resistant walls, floors, and doors...
Rubble masonryRubble masonry is rough, unhewn building stone set in mortar, but not laid in regular courses. It may appear as the outer surface of a wall or may fill the core of a wall which is faced with unit masonry such as brick or cut stone....
Stone wallStone walls are a kind of masonry construction which have been made for thousands of years. First they were constructed by farmers and primitive people by piling loose field stones in what is called a dry stone wall, then later with the use of mortar and plaster especially in the construction of...
StonemasonryThe craft of stonemasonry has existed since the dawn of civilization - creating buildings, structures, and sculpture using stone from the earth. These materials have been used to construct many of the long-lasting, ancient monuments, artifacts, cathedrals, and cities in a wide variety of cultures...
TuckpointingTuckpointing is a way of using two contrasting colours of mortar in brickwork, one colour matching the bricks themselves, to give an artificial impression that very fine joints have been made.-History:...
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External links