Type: Process Essays
Sample donated: Philip Cook
Last updated: May 12, 2019
2.1 INTRODUCTION OF BUILDING MAINTENACEBuilding maintenance is defined as “work undertaken inorder to keep, restore or improve every part of a building, its services andsurrounds, to a currently accepted standard, and to sustain the utility andvalue of the building” (Seeley, 1976). 2.
2 BUILDING MAINTENANCEThe objectives of building maintenance are therefore (Alnerand Fellows, 1990): To ensure that the buildings and their associated servicesare in a safe condition · To ensure that the building are fit for use· To ensure that the condition of the building meets allstatutory requirements· To carry out the maintenance works necessary to maintain thevalue of the physical assets of the building stock and· To carry out the work necessary to maintain the quality ofthe building. BS3811: 1964 defines maintenance as ‘a combination of any actions carried out toretain an item in, or restore it to, an acceptable condition.’ The actionsreferred to are those associated with initiation, organization andimplementation while acceptable condition means a standard that can sustainsthe utility and value of the building. Building maintenance is effort undertaken so as to keep,refurbish or improve every element that is every part of a building, itsservices and surroundings to a currently acceptable condition and to maintainthe utility and value of the facility. It is imperative to the building ownerand the occupier to keep the building and its services in a good state and topreserve its capital asset. Poor maintenance has an adverse outcome on the nation’seconomy. A vast amount of the country’s resources is spent on buildings andfacilities maintenance each year. The amount will keep rising if poormaintenance policies are not eradicated from the system.
In order to achieve an acceptable condition in maintenance,it is necessary to provide sufficient resources in finance, manpower andtechnology. When the deciding resources are acquired, it is vital to study thetypes of buildings to be maintained and the standards required to maintain theutility and worth of the building. 2.2.1Types of Maintenance Thereare several strategic choices available to management to efficiently maintain abuilding and many alternative decisions to be considered. For example, thedemand for maintenance could be reduced by dealing with the actual cause offailure and recognizing its consequences. For instance, it may be necessary todecide whether to repair or replace an item, and whether to carry out periodicmaintenance at fixed intervals or simply to respond to the requests of theusers. Thus, building maintenance can be divided into three strategies (Horner, et .
al , 1997 ) : 1. Corrective2. Preventive3.
Condition-based Figure 2.1 types of maintenance (Source:Horner, et. al , 1997) 2.2.2 Corrective Maintenance Correctivemaintenance is the simplest type of maintenance strategy, where an element in abuilding is used until it breaks down. It covers all activities, includingreplacement or repair of an element that has failed to a point at which itcannot perform its required function. Corrective maintenance is sometimesreferred to as failure-based or unplanned maintenance. Corrective maintenancetasks often takes place in an ad hoc manner in response to breakdowns or usersrequests (David and Arthur, 1989).
Thus, corrective maintenance can beextremely expensive for two reasons: · The failure of an item can cause a large amount of consequentialdamage to other elements in the building. For example, failure of the roofcould cause damage to the ceiling and the interior of the building.· Failure of an item can occur at a time which is inconvenient toboth the user and the maintaining authority. This can make manpower and spareparts planning extremely difficult. 2.2.3 Preventive Maintenance Preventive maintenance was introduced to overcome the disadvantagesof corrective maintenance, by reducing the probability of occurrence of failureand avoiding sudden failure. This strategy is referred to as time-basedmaintenance, planned maintenance or cyclic maintenance.
Preventive maintenancetasks are performed in accordance with a predetermined plan at regular, fixedintervals, which may be based for example an operating time. Such a strategy isfrequently applied to external or internal paint work. The following are theadvantages of preventive over corrective maintenance (Raymond and Joan, 1991) :· Maintenance can be planned ahead and performed when it isconvenient to the building’s user.
· Maintenance costs can be reduced by avoiding the cost of consequentialdamage· Downtime, the time that an element of the building or the wholebuilding is out of service, can be minimized so the habitability of thebuilding can be increased· The health and safety of the user can be improvedNevertheless, preventive maintenance has some disadvantages whichmust be minimized (El-Haram, 1995):· Planned maintenance is performed irrespective of the condition ofthe building elements. Consequently, a large number of unnecessary tasks willbe carried out on elements that could have remained in a safe and acceptablecondition for a much longer time.· The condition of an element may end up worse than it was before, asa result of human error during the execution of the maintenance task. 2.2.4 Condition-Based Maintenance Condition-based maintenance is defined as: “Maintenance carried outin response to a significant deterioration in a unit as indicated by a changein monitored parameter of the unit condition or performance” (Kelly and Harris,1978).
In condition-based maintenance concept, the principal reason forcarrying out maintenance is that there is a change in condition and/orperformance of an item. A condition survey is used to determine the actualstate of each constituent item in a building before the optimal time to carryout maintenance is determined.Aconstant task of monitoring the building’s elements such as the walls, floors,roof and service equipment are needed to identify which element or piece ofequipment requires maintenance. Then the maintenance tasks will then be plannedand determined based on this information. The condition of an item must bemonitored to identify whether there is any evidence of change from a normal toan abnormal condition to make this strategy works effectively. This could be performby choosing the factor which can be best described the state of the article andobserving changes using suitable condition monitoring tools. Conditionmeasurements can vary from a simple visual check to more advanced examinationusing an assortment of condition monitoring tools and techniques. 2.
2.5 Maintenance StrategyThe simplest method to reduce or cut maintenance costs is to stopdoing maintenance. This method is simple but has dire consequences. Thus, theaim of any maintenance approach is to carry out as little maintenance aspossible while at the same time conserving the accessibility of the servicesfacilities, the building elements and the whole building. In simple terms,maintenance should be carried out only when necessary to ensure the continued,safe and profitable use of the building at acceptable levels. The mostdifficult task facing maintenance management is to determine an appropriatemaintenance strategy that will brings an optimal approach to reducing thefinancial expenditure and total life cycle costs.Currentbuilding maintenance strategies, whether based on planned or unplannedmaintenance, are most likely to be budget driven.
This means that maintenanceis carried out according to actual need, but is dictated by financial prioritiesdecided at the time or during the previous 12 months. Although theoreticallythe budget should be built up as a result of estimated needs, it is almostinvariably based on previous years’ figures, modified for changes in the numberof buildings, specially agreed programs of planned maintenance and inflationforecasts (Speeding, 1978). Three methods are currently used for constructing abudget for estate-based management organizations, none is entirely satisfactoryand each produces a different budget (Lee, 1987):· Base this year’s budget on last year’s expenditure with anallowance for inflation.· Use the Department of Environment (DoE) or other formula forcalculating the maintenance element of the estate budget.
· Use a stock condition survey to quantify the size of themaintenance task. In contrast to the way that current building maintenance strategiesare selected, the new maintenance management approach is based on the failureconsequences of each item in a building. Thus, the objective of maintenancemanagement is to prevent, to minimize and to repair building defects byenhanced planning and implementation using appropriate materials and tools atthe right time and minimum total life cycle-cost (Horner, El-Haram and Munns,1997). Its objective is to determine the best combination of maintenancestrategies for a building by selecting the optimum maintenance strategy foreach individual item in the building, taking into consideration health, safetyand satisfaction of the user and the costs of maintenance tasks.
Items shouldbe divided into two categories that are significance items and non-significantitems. The definitions of these items are (Horner, El-Haram and Munns, 1997):· Significant items are those whose failure affects health, safety,environment or utility (including cost)· Non-significant items are those items whose failure has nosignificant effect. This means that the failure affects neither health, safety,environment nor utilityCorrectivemaintenance is most likely to be the appropriate maintenance strategy for(Horner,El-Haram and Munns, 1997): · Non-significant items· Utility significant items whose condition cannot be monitored andfor which the cost of applying time-based preventive maintenance is less thanthe cost of applying corrective maintenance Time-basedmaintenance is most likely to be the appropriate maintenance strategy for(Horner, El-Haram and Munns, 1997):· Health, safety and environmentally significant items whosecondition cannot be monitored· Heath, safety and environmentally significant items whose conditioncan be monitored, but for which the online condition monitoring techniqueseither are not available or are not cost effective· Utility significant items whose condition cannot be monitored andfor which the costs of applying time-based maintenance is less than the cost ofapplying corrective maintenance. Condition-basedmaintenance is most likely to be the appropriate maintenance strategy for(Horner, El-Haram and Munns, 1997):· Health, safety and environmentally significant items whosecondition can be monitored and for which on-line condition monitoringtechniques are available and cost-effective· Utility significant items whose can be monitored and for whichcondition-based monitoring techniques are available and cost-effective· Utility significant items whose condition can be monitored and forwhich the costs of applying condition-based maintenance is less than the costof applying corrective maintenance 2.2.6 Consideration of Maintenance at Design StageThe importance of considering maintenance at the design stage of abuilding project is now generally recognized and the building maintenanceconferences and seminars.
It is at the design stage that the maintenance burdencan be positively influenced for better or for worse. Skillful design canreduce the amount of maintenance work and also make it easier to perform, thusgood maintenance begins on the drawing board. Ideally the design team shouldaim to produce a building which is attractive, functionally efficient andconstructability sound with a minimum of maintenance (Seeley, 1976). The design of the building will not only affect the initial cost ofthe building but will also has large impact on the maintenance cost. Buildingsthat are designed with numerous design defects would incur maintenance costthat would surpass the initial cost of a building.It is significant that the there are effective communicationbetween client, designer, contractor and those in charged with buildingmaintenance.
Obsolete administrative procedures often cause various parties tothe building contract failing to realize the importance of other functions inthe overall concept. This will cause disturbance and irritation to maintenancepersonnel when taking over new buildings and finding themselves faced with baddetails, poor choice of finishes and materials.Regrettably, designers seldom have a lasting interest in thebuildings they produce and hence there are not aware with the maintenanceproblems that resulted from bad design. There should be a maintenance personnelinvolved in the design teams and provide feedback of maintenance andperformance information from users and maintenance organizations to the designteams.Substantial loss of time and interruption of activities can resultfrom the failure of building components or alterations made necessary by poordesign. Education for the designer in the appreciation of maintenancerequirements and costs in use techniques could be most fruitful. Designerscould contribute significantly to a reduction in maintenance costs if theyasked four questions when designing each component or part of building (Seeley,1976):.(a) Howcan it be reached? (b) How can it be cleaned? (c) How long it will last? (d) How can it be replaced? Poor detailing at the design stage could result in high maintenancecost, including insufficient allowance for expansion or contraction, unsoundfoundations, poor jointing between different materials and poor access orfacilities for repairs.
Sometimes the failures resulting from faults in designcannot be cured permanently and remain a continuing nuisance throughout thelife of the building.The designer can refer to an individual designer or a professionalteam with aleader or coordinator. The design team normally comprises thearchitect, quantity surveyor, structural engineer, mechanical engineer andelectrical engineer. 2.3 BUILDING DEFECTS A defect may be considered to be a failing orshortcoming in the function performance, statutory or user requirements of abuilding, and might manifest itself within the structure, fabric, services orother facilities of the affected building.
When an inspection or survey isbeing undertaken, the set of requirements for the particular building type or usewill help to set performance benchmarks against which the building can bemeasured. Where a performance benchmark is not achieved, this indicates adefect or deficiency, the severity of which is gauged by reference to thebenchmark (Watt, 1999). The rigorousness of a building defect and therelated levels of damage, deterioration or decay currently present or expectedto affect the building and its occupant are similarly related to theperceptions and expectations of the owner and occupier, and to various otherstakeholders with interests in the well-being of the property. The defect, orthe action required to reduce or remove its effect on the building, willtypically be ranked according to a pre-determined set of priorities for repair,maintenance or other works to improve either performance or capability. The various elements and associated serviceinstallations that make up a building, together with the contents that allow itto be used and enjoyed, are susceptible to various forms of defect and fault.Past and present research has helped to identify the principal causes, yet manyof the problems relating to poor-quality design, construction, repair andmaintenance continue to reduce the utility and value of the existing buildings. 2.3.
1 Causes of DefectsA building may be defined as an imperfectiondeficiency or fault in a building element or component which adversely affectsits functional performance or appearance. Some defects are the naturalconsequence of ageing and normal use but many premature failings can be tracedto a lack of proper skill and care. A BRE study concluded that over 90 percentof building defects could be explained partly or wholly as the result ofreadily identifiable faults in design or construction which could have been foreseenand hence prevented. Broadly, the causes may be attributed to the following(Lee, 1987):1. Inadequate brief. It is often said that defects start on thedrawing board but in some cases they can originate at an even earlier stage.For example, the brief may lay down totally unrealistic cost limits or fail togive vital information on the functional requirements of the building. Usuallythere is no indication of the likely period of use nor of the client’s attitudetowards maintenance.
2. Faulty design decisions. The most common faults may be grouped asfollows:· Failure to follow well established design criteria in the choice ofstructural system and selection of materials. · Ignorance of the basic physical properties of materials, e.
g.failing to make allowance for the differing thermal and moisture movements ofmaterials used in combination.· Use of new materials or innovative forms of construction which havenot been properly tested in use. This is often the result of uncriticalreliance on manufacturers’ literature quoting simulated laboratory tests.· Misjudgment of user and climatic conditions under which thematerial will have to perform.· Complex details which have a low probability of successfulexecution on an open building site.· Poor communications between different members of the design andconstruction teams.The fault may be traceable to component manufacturers, specialistsub-contractors and consultants as well as the main designer.
A less obvious design fault is the failure to consider the casewith which components can be maintained and eventually replaced. For example,little thought is given to the standardization of components in order to reducethe need to carry a large variety of spare parts or to ensuring that access canbe easily gained for servicing and cleaning. 3. Construction methods The conditions under which construction takes placeare often far from ideal and, coupled with an emphasis on speedy completion,can result in careless and skimped work. Although the BRE study mentioned earliershowed that only a small proportion of defects were attributable to faultymaterials it is apparent that some manufacturers of do-called high technologycomponents have little awareness of the rig ours of a building site or thestandards of accuracy achievable under such conditions.
Thus, whilst thematerials may be perfect on leaving the factory they can quite easily bedamaged in transit, loading and unloading, unsuitable conditions of storage onsite and hoisting and placing in position, many such defects could be avoidedby ensuring greater care at all stages in the process, proper training ofoperatives, and closer supervision. To tackle this problem the constructionindustry is beginning to introduce the quality assurance techniques developedin other industries such as Quality Assurance (QA) groups and circles (QC). 4. User activities. Defects may be caused by unintentional misusethrough a lack of information on the correct mode of use, or by deliberate actsof vandalism. The solution is to provide the designer with more information onthe degree of severity of use so that a better match can be made between therobustness of the fittings and finishing and the condition of use. Also,certain defects may be related to the social attitudes and financialcircumstances of the user,e.
g. condensation is affected by the amount of moneyspent on heating and ventilating, and the occupancy pattern. 5. Maintenance. Incorrect identification of the true cause of adefect, and inappropriate remedial work, will not only do nothing to rectifythe original defect but may substantially worsen the condition of the building.Similarly, lack of care in carrying out repairs and inspections may be thecause of defects in previously satisfactory elements, e.g.
walking on unprotectedfelted flat roofs can drive the gravel into the felt, causing splits and cutsleading to premature leaking. The life of building elements and components canbe extended considerably by adopting a planned maintenance approach so thatproblems can be identified in their early stages and preventive maintenancecarried out to avoid early failure. Current training in design needs to concentratein what to do rather than what not to do. A similar situation exists intraining in construction techniques, where the craftsman is instructed how bestto undertake a particular operation but, to a lesser extent, in the dangers ofdeviation from an accepted technique. Understanding of the likelihood ofdefects through inadequate design or construction is taught implicitly ratherthan explicitly. The level and nature of defects in building constructioncurrently encountered suggest that more guidance is required on the avoidanceof failures.
A need is seen, too, for such guidance to be a positive part of a trainingcurriculum. It seems better to aim at identifying the principal defects andtheir causes which, if wholly eliminated, would prevent the great majority ofthe defects which currently occur, save occupants of buildings much annoyanceand discomfort, and reduce the national bill on maintenance and repair byscores and, possibly, by hundreds, of millions of pounds annually.