Causes of Brick Deterioration and Decay in Buildings

Causes of Brick Deterioration and Decay in BuildingsIntroductionMost separate of the construct argon built from the brick. Nowadays, the brickwork cope flights wargon commonly founded in expression. The riddle was get frequently effective and serious. Seriously of the brickwork defects whitethorn cause a lot of problems to the occupants. The chief(prenominal) problem encountered in edifice with a traditionalistic stunned keister(a) bearing fence of brickwork and c over inside bearing bodily social system is caused by differences in the temperature and wet-induced faecal matter. Crack whitethornbe be discoered in sea debates and solutions let to be found. (L.G.W.Verhoef, 2001)Brickwork defect emits in construction has a multifariousness of reasons. This is perhaps not surprising when one considers the wide range of differences bricks and proficiency in construction of relieve oneselfing, differences in the construction situations and the varied occupational o r possessor used of the completed expression.Brickwork leave alone drop and decay if not properly primary(prenominal)tained. Such deterioration bath be caused by a number of factors and push aside take various(a) forms. The main signs that brickwork is suffering atomic number 18 surface festering and staining, flush, loosed brick suit qualified dislodged, crack appears put down the bricks or trench daub and etc (Moses Jenkins, 2007).In this electric ray chapter, the dissimilar types of the brickwork defect exit be stopd. This chapter gave an overview of various types of the brickwork defects and lowstanding the brickwork defects. To identify the disparate types of the brickwork defects give gain well for the occupants or owners to find out the causes of the defects and take the suitable remedies order in the in force(p) way.Define bricksBrick is the textiles that commonly use to build the buildings environ. Clay bricks be the tumefy-nigh common brick ty pe. It is made from the spine and trunk and uniformly burnt at temperatures between 800C and 1200C. Surface finishes ar al or sotimes applied e.g. glistening bricks. Glazed bricks be still being produced in quantity and provoke be obtained from a major English brick manufacturer and supplier. Calcium Silicate bricks is fabricate from sand-lime (calcium silicate). The bricks ar pressed under great imperativeness and steamed in an autoclave. The bricks ar smooth, fine textured and light in colour. The brick colour is produced from corporeal source, composition and firing temperature.The sizing of bricks over time has repositiond considerably. Some archean medieval bricks were 13 inches by 6 inches by 2 inches. By the late 15th century a brick 9.5 inches by 4.5 inches by 2 inches became the norm and a charter in 1571 stipulated 9 inches by 4.5 inches by 2.25 inches. By the 18th century, 8.25 inches by 4 inches by 2.5 inches brick was introduced. Modern bricks be 8.5 inche s by 4 inches by 2.5 inches which following metrication translated to 215mm by 102.5mm by 65mm. Modern bricks is the brick that most of the building using in nowadays.Defect of surfaceOversized bricks are caused by scurvy material selection and readying or underfiring. Under size bricks are caused mainly by unequal material preparation, defective moulds and overfiring.Defect of shapeThe causes of these defects are many. These are including poor preparation of moulds or moulding technique, faults in stacking, rough handling and petulant teetotaling. If the bricks are considerably over burnt, early fusion takes place and the bricks, called burrs, lie with out of the kiln or clamp stuck together. Burrs are suitable only for unmanageablecore calculates.Defects of bodyFaults in the raw material body washbasin defecate rise to defects such(prenominal) as fault, bloating and laminations. Cracking and warping of bricks, causing incipient weakness, maybe repayable to exposure of green bricks to direct sunlight or rapid teetotaling winds. Similar declare testament be produced by lay green bricks into the kiln too soon. Large cracks maybe caused by rain getting onto hot bricks.Defect of AppearanceThese defects are caused primarily by faulty electrifys in the case of wire-cut bricks. Dark spots are caused by the front end of unevenly distri plainlyed iron sulphide in the clay.Brick surround elimination any case in a structuralbrick wall which risks having garbled the bond courses in the wall, and any thrust in abrick veneer wall which has broken or loosened the connections between the veneers to the underlie structure are potentially dangerous and risk collapsing masonry.Bulging brick wallThis is likely to be a bond-brick or bond-course failure. This defect is potentially extremumly dangerous and essential be very urgent to take action. If not, it tail causes the building all of a sudden collapse.Cracks and Bulges in brick wallsFrost and earth despatch squirt push a below-grade brick origination wall inwards. The wall is a lottimes bulged inwards as well as showing level and step wisecrack and loose bricks over the bulged flying field. The molest materialises from slightly above background signal level to roughly the freeze line.Cracks and loose bricksNormally, crack and loose bricks are cause by icing, settlement, expansion, aslope and stair-stepped. Those defects very much happen at building corners where roof spillage is keep voltaic piled. unbend bricks and missing or scattered daubThis is the movement where plaster is intemperately washed-out by roof spillage or former(a) weewee system movement against the foundation. Loose and lost bricks may in any case occur where woodwind blocks, primarily set into a wall to permit nailing of interior components, is modify by insects or decay. Similarly, if wood joists are wrongfulnessd and bend too or collapse (insect damage, rot, fire) the col lapsing joist commode, as its in-wall end moves, damage the foundation or building wall. Fire cuts on wood joists in brick walls were intended to sully this damage source by angling the end of the joist where it was set into the wall pocket.Sand-blasted bricksWhich have been cleaned of old paint, algae, or stains using superior pressure sand blasting or possibly even very extravagantly pressure irrigate blasting tolerateister be permanently damaged by loss of the harder surface of the bricks which had been provided by their original firing. Once the softer indwelling brick has been capable, the bricks entrust be more inc lie to absorb water and to suffer water and frost damage. Sandblasting brick is considered a poor pract applesauce in building run and maintenance.Spalling bricksSpalling is caused by water and frost, such as water leaking into a brick structure at any entry point a crack, a brick which has lost its hard surface, or at openings by window and door penetrat ions. plainly beware to the highest degree caulking brick.Exfoliating-rust damage to brickMasonry wall occur these defects when brick walls have been haywirely caulked where caulking should have been omitted. The most common example of this defect is the damage that occurs to a brick wall when a steel lintel over a window or door is caulked tightly between the brick and the steel. moisture penetrating the brick wall through with(predicate) cracks or daub joints is trapped most the steel lintel. Rust developing on steel lintels has tremendous lifting force as the rusting exfoliating metal go bys, sufficient to crack and damage bricks around lintel.Improper repair trench mortaron brickworkDuring repair work, tuck pointing bricks, or re-pointing bricks can cause surface spalling of bricks if the mason uses a too hard mortar with high portland sate mortar on soft brick in a climate exposed to freezing weather. The high portland content authority that the mortar bequeath be not only harder, just now more waterproof than the surrounding brick. Water trapped around the hard mortar can freeze leading to surface spalling of the bricks. This is curiously likely to be seen when a wall has been tuck pointed using hard high-portland mortar where originally a soft high-lime mortar was used and where the original bricks were soft.Salts on brickworkSalts are a major cause of deterioration. Salt can enter bricks through contaminated water ingress. In coastal areas brininess can behave from the sea and, in winter, the nearby application of road salt is a constant threat. Salt is damaging because it creates a steady expansion of crystals inwardly the bricks. This can eventually force the structure of the brick apart. The source of salt can occur from within the bricks themselves or from the application of contaminated mortars or renders. Brick lined chimney flues are also vulnerable as sulfates can be introduced when flu gasses condense. This is a common def ect where a chimney has been certain(a) without adequate ventilation.Efflorescence on brickworkEfflorescence appears as a whiteness powdery deposit on the brick. It is a phenomenon that dissolvable slats dissolved in water are carried, deposited and gradually accumulated on brick surfaces to form an ugly scum. Without water efflorescence cannot occur. The fat-soluble salts may be originated from the raw material of bricks. But in most cases, efflorescence is caused by salts from the external sources such as ground water, contaminated melody, mortar ingredients and other materials in contacts with the bricks. To belittle the risk (it can never be completely vacateed in brickwork exposed to weathering) the building detail should be designed, as far as is possible, to avoid saturation. In other words good overhangs, copings and sills with drips all take to be considered. Efflorescence can be helped on its way by sponging ingest the wall with clean water (avoiding substantial modifyting) or dry brush with soft brushes. Any other treatment should be avoided as it may disfigure the bricks.Frost Attack on brickworkFrost glide path often occurs when very cold weather immediately follows a very wet spell. When porous materials become saturated and the temperature drops below freezing the formation of ice causes stresses which some bricks cannot be resist and chap or spalling occurs. Clay bricks are classified as frost resistant, moderately frost resistant, and not frost resistant. Calcium silicate bricks are not generally at risk although it is rash to specify bricks with a compressive strength.Thermal movement on brickworkEvery materials expand or contracts as the temperature of the material changes, typically expanding as its temperature increases and contracting as its temperature decreases. Different materials expand and contract at different rates when they abide similar changes in their temperatures. Brick veneer can expand and contract approximate ly. When determine the expansion or contraction of a brick veneer, it is important to remember the returns of the sun on materials. The capacity from the suns rays raises the temperature of a material well above the air temperature. On a day when the air temperature is 32 F, the energy from the sun can raise a walls temperature to above 100 FThermal expansion failures in structural or veneer brick wallsA separate factor that can cause very super movements and extended damage to brick structures or brick veneer walls is the caloric expansion which occurs across a long or tall brick wall when that wall is heated by sun exposure. The photographs show significant thermal expansion damage in a long brick structure.Significant breaks and gapsat vertical brick mortar joints due to thermal expansion and perhaps some frost and water damage. impression of thermal expansion damage to a brick wallFigure1 Significant breaksHorizontal slip breaksin brick mortar joints,exposing reinforcing w ire to rust, exfoliation, and additional damage from those forces as the exfoliating wire produced still more pressure on the mortar joint.Photograph of a collapsed brick strudctural wallFigure2 Horizontal breaksStep crackingfollowing mortar joints near the building corners and where the wall movement was resisted by first story intersecting brick walls contiguous at right angles the middle section of the long brick wall.Photograph of thermal expansion damage to a brick wallFigure3 Step crackingCracks and broken bricks at the intersections of brick walls and openings.Photograph of thermal expansion damage to a brick wallFigure 4 Cracks and broken bricks(InspectApedia, 2007)Moisture movement on brickworkMoisture affects all porous masonry materials, including brick, mortar and concrete masonry units but in very different ways. These pictures must(prenominal)(prenominal) be considered when a combination of these materials is used, such as when brick rests on a concrete foundation, brick veneer units are used with block back up, and when brick and architectural concrete products are used in the same wythe bands of precast concrete or architectural concrete block in a brick veneer. after their initial mixing or casting, mortar, poured-in-place concrete and concrete masonry units cut back as the curing of the Portland cement proceeds. This is an unavoidable consequence of the curing of concrete products and is becomed in design.Sulphate attack on brickworkMost ordinary clay bricks engage sulphates of sodium, magnesium or calcium. These salts are soluble in water in water, calcium sulphate being less(prenominal) soluble than the other two. Normally, these sulphates are seen as the harmless efflorescence which affect appearance only and need simply to be brushed away. In theory, most brick walls with mortars based on OPC (Ordinary Portland Cement) are liable to sulphate attack. The most vulnerable walls are earth-retaining walls and restriction walls but sulp hate attack is a problem also on rendered, and on facing brickwork.On rendered brickwork, sulphate attack is manifested by cracking of the rendering, the cracks being mainly flat and corresponding to the mortar joints below. The rendering may adhere quite well to the bricks early in the attack but areas are likely to become detached as the expansion of the underlying brickwork causes severance of the bond between the two material. (H.J.Eldridge,B.Sc.1976) calx staining on brickworkLime staining occurs when calcium hydroxide is deposited on the face of brickwork. Lime staining will quickly absorbs carbon dioxide from the air and becomes calcium carbonate. It is just about insoluble and can only be removed by secure and courtly treatment. The calcium hydroxide can come from three main sourcescalcium hydroxide caused by the hydration of Portland cementfrom hydrated lime added to mortarfrom brickwork in contact with wet concreteporosity on brickPorosity is an important characteristi c of brick. In contrast to other moulded or pre-cast building materials, the porosity of brick is attributed to its fine capillaries. By virtue of the capillary vessel effect, the rate of moisture transport in the brick is ten times faster than in other building materials. Moisture is released during day-time and re-absorbed during night-time. The ability to release and re-absorb moisture by capillary effect is one of the most useful properties of brick that helps to regulate the temperature and humidity of atmosphere in a building. This distinctive property makes brick an admirable building material, particularly suitable for buildings in the tropics. On the other hand, all porous materials are sensitized to chemical attacks and liable to contamination from weathering agents like rain, running water and polluted air.Crack in brick faces/firecracksThe finished appearance of clay brick can vary greatly, this is because dependant on clay and the manufacturing process. Some products c ontain cracks of change degree (sometimes referred to as firecracks) as an inherent feature. Firecracks are usually perceptible on the product as delivered. However, firecracks can be masked by the texture and surface sands used in the manufacturing process becoming visible after bricks are laid as a issuing of natural weathering of exposed brickwork.Dampness of the brick wallMore or less permanent dampness showing more clearly on the internal wall surface from ground level up to a superlative degree of about 750mm, but may be higher in solemn cases or if the outer face is covered with a non-porous finish. The decorations may be damp, blistered or discoloured, or, if dry, may have been pushed off the wall by a film or salts which will often be seen as a fluffy crystalline growth. The possible causes of dampness in the brick wall are overlook of dpc (damp proof course), by-passing of the dpc, Failure of the dpc material.Brick growth and expansion gaps in brickworkBricks tolera te long-term permanent expansion over time. This expansion continues for the life of the brick, but the majority of the growth occurs early in its life. Most general purpose bricks have a coefficient of expansion in the range of 0.5-1.5mm/m (millimeters per meter) over fifteen years. envisioners can use the values of the coefficient of expansion to accommodate for the growth of bricks by the size and spacing of the control joints. The provision of control gaps or articulation joints between separate of the structure during construction will accommodate movements within the structure over time. Numerous sources of movement exist and embroilThe change in size of building materials with temperature, loading conditions and moisture contentThe differential change in size of building materials (for example, cement products shrink over time, whilst clay bricks expand slowly over time)Foundation and footings movementFrame movementFrame shorteningTemperature movementInternal horizontal and vertical movementCauses of the brickwork defectsIntroductionBrick deeds are used primarily in the construction of walls. To construct the brick wall required many skills, design, experience, selection of material, and technique. insufficiency of all expertise may cause the brickwork defects or failure of the building. The defects that occur in brickwork maybe the moment of inherent faults, deficiencies in production, design, materials or workmanship, and attack by environmental agents.After the brickwork has been constructed, it maybe meets of various requirements, climate, loading, and occupational in use. It is not surprising that defects happened or occurs frequently.In this sub chapter, the causes of the brickwork defects will be list out. To find out the actual causes of the brickwork defects will be easily for the occupational to take the right remedies immediately and reduces the brickwork defects happen.Selection of bricksThe choice of bricks is often influenced by the pr ice but the quality required must also be carefully considered in order to avoid defects developing during the service life of the material. Therefore, the selection of suitable bricks for any particular purpose has often to be a trade-off between appearance and strong suit requirements on the one hand, and cost on the other.This is not always possible to tax the quality of bricks by the colour, variability of colour of bricks of the same source and order of production can often be an indication of strength and durability variations.Storage of bricksBricks on site are rarely kept under adequate cover. Defects in the bricks resulting from the lack of adequate protection on the site are rarely apparent in the first place use. However, bad weather conditions can be detrimental to bricks in that saturation by rain can be responsible for both subsequent efflorescence and decoration defects. water-soluble Salts in BricksUnder burnt bricks contain a high salt content. The salts come fr om the raw clay from which the bricks are made, or are make in the burning process. Most clay bricks contain some soluble salts, but the types and amounts vary appreciably. The effect of the soluble salts on both efflorescence and the more serious problem of disintegration of bricks themselves are largely governed by the strength and pores structure of the bricks.Sulphate attackSulphates are salts which are of course present in industrial waste, gypsum product, clay bricks, flue condensates and in some ground waters. In persistently damp conditions, sulphate will act slowly with tricalcium aluminate forming a compound called calcium sulphoaluminate. This reaction causes the cement mortar or render of the brickwork to expend and eventually disintegrate.Solar Radiationdarn drying out of reproach by trees is the most common reason for cracking in brickwork, some clay are also very susceptible to drying out by direct solar radiation. The northern facing wall is the most likely to be affected and stepped diagonal cracking is the most common symptom, usually occurring at the north east and north western corner of the building. (Greg Loveder, 2000)Migration of moistureThe movement of moisture beneath a building can produce the phenomenon know as long term bean plant and saucer effect. The dome effect is a slow heaving of the territorial dominion caused by movement of moisture from the perimeter of the house to its centre, and the saucer effect is moisture moving in the opposite direction, from the centre towards the perimeter. The dome effect causes the walls to tilt outwards and the restraining influence of the roof produces horizontal cracks on the outside wall. These will be wider on the outside surface rather than the inner.plant of treeSome of the brickwork defects may cause by big trees root that plant nearby the building area. When planning to plant trees, the idea to be considering is the strength of the footings under the house. If lack of strength, t he roots of the trees maybe grow into the ground under the building and cause the brick wall settlement and cracking.Uneven settlement of foundationsWhere a particular monstrous load is placed on the foundation such as a large column, movement may occur as moisture is squeezed out of the soil or the soil readjusts itself. This integration will stop when the soil has finally compacted decent to support the load. Brick wall or masonry wall may crack which may result from movement during compaction.Excessive oscillationDamage caused by vibration from earth tremors, heavy traffic or pile driving is fairly rare, however if the vibration is great enough to actually cause the foundation to move, brickwork cracking or defect can occur. The crack will show up irregularly if the sources of the vibration cannot be removed. (Greg Loveder, 2000)Additional buildingBuilding an addition building onto a house or add more storey of houses can impose a load intensity on the soil different that whi ch is there already and so cause differential settlement. Even if the loading intensities are similar, the difference in time between when the two settlements occurred can be enough to create the brick wall cracks.Approach of designDesign of brick wall is very important. The designer must have the knowledge about the brick experience in chosen the types of brick to be used. The designer must be fully aware of the clients needs. Defects often occur because of a lack of understanding of the different types of bricks and the rule of construct the brick wall.Lack experience of workerWorkers in the masonry construction is not in strict accordance with the construction and standards, masonry mortar is not full, especially in vertical mortar joints are not full, and even produce dense seam, seam permeability. In addition, the dry brick on the wall, mortar in the brick water was absorbed, causing low strength of mortar, brick and mortar separation, so that the overall stiffness of masonr y fell, gray mortar joints crack.OverloadingCracks of brickwork may result from overloading of the ground on which the building rests, or of the building itself or parts of it. Releasing the load does not necessary allow the masonry wall to retrogress to its original state since the overloading may have been partially accommodated by a permanent compaction of the bricks. The forces responsible for the overloading may be of external origin, such as excessive wind, or may be internal, such as those arising from the installation of excessively heavy equipment for which the masonry wall was not designed. A change of occupational may have same results.Lack of maintenance guardianship must be taken for all the building to minimize the cost of repair work for seriously defects happen. Lack of maintenance will make a small cracks or defects on brickwork change to more serious and serious.Improper soil analysis and preparationWhen a constructor chooses an area of land to build on, it is i mportant to do some sort of soil analysis and preparation. The analysis will provide the developer and/or builder with enough information to choose the adequate soil preparation and construction dodging that should be used to develop the land. Improper soil analysis and preparations can be very damaging to a housing development. For example, a builder can discover that the land soil is made up of blabbermouthed soil. If this is the case, houses need to have a foundation that will be able to support the changing pressure and consistency of the soil. This is because expansive soil will swell when wet and then shrink once it dries. If one builds on this type of soil and is not aware of it, there will inescapably be issues to handle. There will be crack in the brick wall or masonry wall. The repair of this is very costly and very intrusive. Unfortunately, the reality is improper soil analysis and preparations happen all the time.Negligence of construction lax construction is an unfo rtunately common occurrence. A builder has to be very careful when choosing a contractor or subcontractor. A builder will sometimes use one contactor for various projects. A contractor may have skills to install floor tiles but not the know how to build a brick wall. The responsibility can fall on several parties when there is a defect, and thats up to your attorney to determine.Movement of the groundMining subsidence, landslips, earthquakes, or moisture changes of shrinkable clay soil may cause the movement of the ground. The brick wall of the building will be crack because the wall of building has become displaced from the rest without any change in actual size of the materials. In theory, this is possible to reconnect the displace parts to bring the building back to its original condition but in practice this seldom can be done.Acid rainAcid rain is precipitation that is much more venomousic than normal rainfall, and the acid rain is usually caused by pollution such as sulfur an d nitrogen emissions. Several different mechanisms are operant in the deterioration of brick masonry through the action of acid rain. The bricks are susceptible to acid rain through the selective radioactive decay of their glassy phase. The mortar is affected mainly by the reaction of the chalky components. The soluble salts resulting from these reactions, in solution with rain water or condensed moisture, will migrate through the porous matrix of the masonry. In the places where the water evaporates the salts will be deposited. Repeated dissolution and re-crystallization of these salts leads to the mechanical disruption of the masonry structure. Since the salts will concentrate in the more porous material, either the brick or the mortar will be more seriously affected, depending on their relative porosity.Environment both aspects of the environment have been considerably which is wind and temperature. This is because they cause loading to be applied to the structure. The strong wi nd may cause the brick wall or the whole building move, this may cause cracking to the part of the building. The high temperature applied to the brickwork may cause spalling and brick prolong to high temperature can lead to surface vitrification. (A.M.Swoden, 1990)Remedies method of the brickwork defects in buildingIntroductionAs known early, brickwork is one of the largest parts of most of the building. The strength, stability, and durability of brickwork are very important. If lack of all those factor, the brick wall or masonry wall maybe fall down or collapse suddenly.If the brickwork occurs any cracking or defects, the right method of remedies must be taken immediately. This is to ensure that the occupational or owner use the building under safety and healthy purposes.Brickwork will deteriorate and decay if not properly maintained. Such deterioration can be caused by a number of factors and can take various forms. The main signs that brickwork is suffering are surface growth and staining, efflorescence, loosed brick becoming dislodged, crack appears throw the bricks or mortar and etc. So, the right remedy must be taken to ensure the brickwork do not decay and deteriorate. (Moses Jenkins, 2007)In this sub chapter, the remedies method for various types of defects will be list out. This is to avoid the brickwork defect getting serious in building in construction industry. The defects of brickwork must be repair immediately, if not the defects will be more serious. For example, cracking can be due to expansion or shrinkage the clay brickwork itself.Remedies of efflorescenceEfflorescence can be minimized by place dry bricks and by speeding up the drying process after the bricks have been laid by providing good ventilation. The salts that cause efflorescence are soluble in water. Hosing with water will cause the salts to dissolve and be re-absorbed into the brickwork, and then reappear when the brick wall dries out again. Acid or alkaline treatments are not rec ommended as they increase the salt content of the wall. The best method is simply brush off the deposit with a stiff dry bristle brush after the wall has dried out. Then shnorr the surface with a damp synthetic chamois or high suction schnorr. Use very little water and rinse sponge frequently in fresh water.Remedies of sulphate attackThe effects of sulphate attack manifest themselves as expansion of the jointing mortar. On rendered walls the signs are horizontal cracking of the rendering with portions falling off. Advanced stages of attack may make the structure unsafe. When rebuilding is necessary, the bricks use should be of low sulphate content and the mortar should be of a mix of 116 sulphate-resistance Portland cement hydrated lime sand. In addition, care should be taken to exclude all conditions of dampness. On rendered walls, the rendering should be removed and the brickwork allowed to dry before reapplying a weaker mix of sulphate-resistance cement, lime and sand.Tackling DecayWhere decay has occurred, take action to rectify the damage will be necessary before this leads to greater problems. The use of chemical treatments to stabilize brick should only be considered with extreme caution. Whilst the defects may be effective initially, there has been insufficient research carried out on the possible long term damage such treatments could have. chemical substance sealants can trap moisture within the brick just as effectively as the claims to keep water out.CleaningCleaning soiled brick buildings should be undertaken carefully. In the past, the use of inappropriate cleaning techniques has resulted in considerable damage being done. If considered essential small scale tests should be employed to measure out the effectiveness and likely damage which could be caused before any large scale work is carried out. There are some guides when doing the cleaning works-Do not re-clean brickwork with the same chemicals unless recommended by the cleani