2.1 out the work necessary to maintain the

2.1 INTRODUCTION OF BUILDING MAINTENACE

Building maintenance is defined as “work undertaken in
order to keep, restore or improve every part of a building, its services and
surrounds, to a currently accepted standard, and to sustain the utility and
value of the building” (Seeley, 1976).

 

2.2 BUILDING MAINTENANCE

The objectives of building maintenance are therefore (Alner
and Fellows, 1990): To ensure that the buildings and their associated services
are in a safe condition

 

·        
To ensure that the building are fit for use

·        
To ensure that the condition of the building meets all
statutory requirements

·        
To carry out the maintenance works necessary to maintain the
value of the physical assets of the building stock and

·        
To carry out the work necessary to maintain the quality of
the building.

 

 

 

 

BS
3811: 1964 defines maintenance as ‘a combination of any actions carried out to
retain an item in, or restore it to, an acceptable condition.’ The actions
referred to are those associated with initiation, organization and
implementation while acceptable condition means a standard that can sustains
the 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, its
services and surroundings to a currently acceptable condition and to maintain
the utility and value of the facility. It is imperative to the building owner
and the occupier to keep the building and its services in a good state and to
preserve its capital asset. Poor maintenance has an adverse outcome on the nation’s
economy. A vast amount of the country’s resources is spent on buildings and
facilities maintenance each year. The amount will keep rising if poor
maintenance 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 and
technology. When the deciding resources are acquired, it is vital to study the
types of buildings to be maintained and the standards required to maintain the
utility and worth of the building.

 

 

2.2.1
Types of Maintenance

 

There
are several strategic choices available to management to efficiently maintain a
building and many alternative decisions to be considered. For example, the
demand for maintenance could be reduced by dealing with the actual cause of
failure and recognizing its consequences. For instance, it may be necessary to
decide whether to repair or replace an item, and whether to carry out periodic
maintenance at fixed intervals or simply to respond to the requests of the
users. Thus, building maintenance can be divided into three strategies (
Horner, et . al , 1997 ) :

 

1.      Corrective

2.      Preventive

3.      Condition-based

 

 

 

 

 

 

 

 

 

 

Figure 2.1 types of maintenance

(Source:
Horner, et. al , 1997)

 

2.2.2 Corrective Maintenance

 

Corrective
maintenance is the simplest type of maintenance strategy, where an element in a
building is used until it breaks down. It covers all activities, including
replacement or repair of an element that has failed to a point at which it
cannot perform its required function. Corrective maintenance is sometimes
referred to as failure-based or unplanned maintenance. Corrective maintenance
tasks often takes place in an ad hoc manner in response to breakdowns or users
requests (David and Arthur, 1989). Thus, corrective maintenance can be
extremely expensive for two reasons:

 

·        
The failure of an item can cause a large amount of consequential
damage to other elements in the building. For example, failure of the roof
could cause damage to the ceiling and the interior of the building.

·        
Failure of an item can occur at a time which is inconvenient to
both the user and the maintaining authority. This can make manpower and spare
parts planning extremely difficult.

 

 

2.2.3 Preventive Maintenance

 

Preventive maintenance was introduced to overcome the disadvantages
of corrective maintenance, by reducing the probability of occurrence of failure
and avoiding sudden failure. This strategy is referred to as time-based
maintenance, planned maintenance or cyclic maintenance. Preventive maintenance
tasks are performed in accordance with a predetermined plan at regular, fixed
intervals, which may be based for example an operating time. Such a strategy is
frequently applied to external or internal paint work. The following are the
advantages of preventive over corrective maintenance (Raymond and Joan, 1991) :

·        
Maintenance can be planned ahead and performed when it is
convenient to the building’s user.

·        
Maintenance costs can be reduced by avoiding the cost of consequential
damage

·        
Downtime, the time that an element of the building or the whole
building is out of service, can be minimized so the habitability of the
building can be increased

·        
The health and safety of the user can be improved

Nevertheless, preventive maintenance has some disadvantages which
must be minimized (El-Haram, 1995):

·        
Planned maintenance is performed irrespective of the condition of
the building elements. Consequently, a large number of unnecessary tasks will
be carried out on elements that could have remained in a safe and acceptable
condition for a much longer time.

·        
The condition of an element may end up worse than it was before, as
a 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 out
in response to a significant deterioration in a unit as indicated by a change
in monitored parameter of the unit condition or performance” (Kelly and Harris,
1978). In condition-based maintenance concept, the principal reason for
carrying out maintenance is that there is a change in condition and/or
performance of an item. A condition survey is used to determine the actual
state of each constituent item in a building before the optimal time to carry
out maintenance is determined.

A
constant task of monitoring the building’s elements such as the walls, floors,
roof and service equipment are needed to identify which element or piece of
equipment requires maintenance. Then the maintenance tasks will then be planned
and determined based on this information. The condition of an item must be
monitored to identify whether there is any evidence of change from a normal to
an abnormal condition to make this strategy works effectively. This could be perform
by choosing the factor which can be best described the state of the article and
observing changes using suitable condition monitoring tools. Condition
measurements can vary from a simple visual check to more advanced examination
using an assortment of condition monitoring tools and techniques.

 

 

 

2.2.5 Maintenance Strategy

The simplest method to reduce or cut maintenance costs is to stop
doing maintenance. This method is simple but has dire consequences. Thus, the
aim of any maintenance approach is to carry out as little maintenance as
possible while at the same time conserving the accessibility of the services
facilities, 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 most
difficult task facing maintenance management is to determine an appropriate
maintenance strategy that will brings an optimal approach to reducing the
financial expenditure and total life cycle costs.

Current
building maintenance strategies, whether based on planned or unplanned
maintenance, are most likely to be budget driven. This means that maintenance
is carried out according to actual need, but is dictated by financial priorities
decided at the time or during the previous 12 months. Although theoretically
the budget should be built up as a result of estimated needs, it is almost
invariably based on previous years’ figures, modified for changes in the number
of buildings, specially agreed programs of planned maintenance and inflation
forecasts (Speeding, 1978). Three methods are currently used for constructing a
budget for estate-based management organizations, none is entirely satisfactory
and each produces a different budget (Lee, 1987):

·        
Base this year’s budget on last year’s expenditure with an
allowance for inflation.

·        
Use the Department of Environment (DoE) or other formula for
calculating the maintenance element of the estate budget.

·        
Use a stock condition survey to quantify the size of the
maintenance task.

 

 

 

 

 

In contrast to the way that current building maintenance strategies
are selected, the new maintenance management approach is based on the failure
consequences of each item in a building. Thus, the objective of maintenance
management is to prevent, to minimize and to repair building defects by
enhanced planning and implementation using appropriate materials and tools at
the right time and minimum total life cycle-cost (Horner, El-Haram and Munns,
1997). Its objective is to determine the best combination of maintenance
strategies for a building by selecting the optimum maintenance strategy for
each individual item in the building, taking into consideration health, safety
and satisfaction of the user and the costs of maintenance tasks. Items should
be divided into two categories that are significance items and non-significant
items. 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 no
significant effect. This means that the failure affects neither health, safety,
environment nor utility

Corrective
maintenance 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 and
for which the cost of applying time-based preventive maintenance is less than
the cost of applying corrective maintenance

 

 

 

 

 

 

Time-based
maintenance is most likely to be the appropriate maintenance strategy for
(Horner, El-Haram and Munns, 1997):

·        
Health, safety and environmentally significant items whose
condition cannot be monitored

·        
Heath, safety and environmentally significant items whose condition
can be monitored, but for which the online condition monitoring techniques
either are not available or are not cost effective

·        
Utility significant items whose condition cannot be monitored and
for which the costs of applying time-based maintenance is less than the cost of
applying corrective maintenance.

 

Condition-based
maintenance is most likely to be the appropriate maintenance strategy for
(Horner, El-Haram and Munns, 1997):

·        
Health, safety and environmentally significant items whose
condition can be monitored and for which on-line condition monitoring
techniques are available and cost-effective

·        
Utility significant items whose can be monitored and for which
condition-based monitoring techniques are available and cost-effective

·        
Utility significant items whose condition can be monitored and for
which the costs of applying condition-based maintenance is less than the cost
of applying corrective maintenance

 

 

 

 

 

2.2.6 Consideration of Maintenance at Design Stage

The importance of considering maintenance at the design stage of a
building project is now generally recognized and the building maintenance
conferences and seminars. It is at the design stage that the maintenance burden
can be positively influenced for better or for worse. Skillful design can
reduce the amount of maintenance work and also make it easier to perform, thus
good maintenance begins on the drawing board. Ideally the design team should
aim to produce a building which is attractive, functionally efficient and
constructability sound with a minimum of maintenance (Seeley, 1976).

 

The design of the building will not only affect the initial cost of
the building but will also has large impact on the maintenance cost. Buildings
that are designed with numerous design defects would incur maintenance cost
that would surpass the initial cost of a building.

It is significant that the there are effective communication
between client, designer, contractor and those in charged with building
maintenance. Obsolete administrative procedures often cause various parties to
the building contract failing to realize the importance of other functions in
the overall concept. This will cause disturbance and irritation to maintenance
personnel when taking over new buildings and finding themselves faced with bad
details, poor choice of finishes and materials.

Regrettably, designers seldom have a lasting interest in the
buildings they produce and hence there are not aware with the maintenance
problems that resulted from bad design. There should be a maintenance personnel
involved in the design teams and provide feedback of maintenance and
performance information from users and maintenance organizations to the design
teams.

Substantial loss of time and interruption of activities can result
from the failure of building components or alterations made necessary by poor
design. Education for the designer in the appreciation of maintenance
requirements and costs in use techniques could be most fruitful. Designers
could contribute significantly to a reduction in maintenance costs if they
asked four questions when designing each component or part of building (Seeley,
1976):.

(a) How
can 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 maintenance
cost, including insufficient allowance for expansion or contraction, unsound
foundations, poor jointing between different materials and poor access or
facilities for repairs. Sometimes the failures resulting from faults in design
cannot be cured permanently and remain a continuing nuisance throughout the
life of the building.

The designer can refer to an individual designer or a professional
team with aleader or coordinator. The design team normally comprises the
architect, quantity surveyor, structural engineer, mechanical engineer and
electrical engineer.

 

 

2.3 BUILDING DEFECTS

 

A defect may be considered to be a failing or
shortcoming in the function performance, statutory or user requirements of a
building, and might manifest itself within the structure, fabric, services or
other facilities of the affected building. When an inspection or survey is
being undertaken, the set of requirements for the particular building type or use
will help to set performance benchmarks against which the building can be
measured. Where a performance benchmark is not achieved, this indicates a
defect or deficiency, the severity of which is gauged by reference to the
benchmark (Watt, 1999).

 

The rigorousness of a building defect and the
related levels of damage, deterioration or decay currently present or expected
to affect the building and its occupant are similarly related to the
perceptions and expectations of the owner and occupier, and to various other
stakeholders with interests in the well-being of the property. The defect, or
the action required to reduce or remove its effect on the building, will
typically 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 service
installations that make up a building, together with the contents that allow it
to 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 many
of the problems relating to poor-quality design, construction, repair and
maintenance continue to reduce the utility and value of the existing buildings.

 

 

 

 

2.3.1 Causes of Defects

A building may be defined as an imperfection
deficiency or fault in a building element or component which adversely affects
its functional performance or appearance. Some defects are the natural
consequence of ageing and normal use but many premature failings can be traced
to a lack of proper skill and care. A BRE study concluded that over 90 percent
of building defects could be explained partly or wholly as the result of
readily identifiable faults in design or construction which could have been foreseen
and hence prevented. Broadly, the causes may be attributed to the following
(Lee, 1987):

1.     
Inadequate brief. It is often said that defects start on the
drawing 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 to
give vital information on the functional requirements of the building. Usually
there is no indication of the likely period of use nor of the client’s attitude
towards maintenance.

2.     
Faulty design decisions. The most common faults may be grouped as
follows:

·        
Failure to follow well established design criteria in the choice of
structural 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 of
materials used in combination.

·        
Use of new materials or innovative forms of construction which have
not been properly tested in use. This is often the result of uncritical
reliance on manufacturers’ literature quoting simulated laboratory tests.

·        
Misjudgment of user and climatic conditions under which the
material will have to perform.

·        
Complex details which have a low probability of successful
execution on an open building site.

·        
Poor communications between different members of the design and
construction teams.

The fault may be traceable to component manufacturers, specialist
sub-contractors and consultants as well as the main designer.

A less obvious design fault is the failure to consider the case
with which components can be maintained and eventually replaced. For example,
little thought is given to the standardization of components in order to reduce
the need to carry a large variety of spare parts or to ensuring that access can
be easily gained for servicing and cleaning.

 

3.     
Construction methods The conditions under which construction takes place
are often far from ideal and, coupled with an emphasis on speedy completion,
can result in careless and skimped work. Although the BRE study mentioned earlier
showed that only a small proportion of defects were attributable to faulty
materials it is apparent that some manufacturers of do-called high technology
components have little awareness of the rig ours of a building site or the
standards of accuracy achievable under such conditions. Thus, whilst the
materials may be perfect on leaving the factory they can quite easily be
damaged in transit, loading and unloading, unsuitable conditions of storage on
site and hoisting and placing in position, many such defects could be avoided
by ensuring greater care at all stages in the process, proper training of
operatives, and closer supervision. To tackle this problem the construction
industry is beginning to introduce the quality assurance techniques developed
in other industries such as Quality Assurance (QA) groups and circles (QC).

 

 

4.     
User activities. Defects may be caused by unintentional misuse
through a lack of information on the correct mode of use, or by deliberate acts
of vandalism. The solution is to provide the designer with more information on
the degree of severity of use so that a better match can be made between the
robustness of the fittings and finishing and the condition of use. Also,
certain defects may be related to the social attitudes and financial
circumstances of the user,e.g. condensation is affected by the amount of money
spent on heating and ventilating, and the occupancy pattern.

 

 

5.     
Maintenance. Incorrect identification of the true cause of a
defect, and inappropriate remedial work, will not only do nothing to rectify
the original defect but may substantially worsen the condition of the building.
Similarly, lack of care in carrying out repairs and inspections may be the
cause of defects in previously satisfactory elements, e.g. walking on unprotected
felted flat roofs can drive the gravel into the felt, causing splits and cuts
leading to premature leaking. The life of building elements and components can
be extended considerably by adopting a planned maintenance approach so that
problems can be identified in their early stages and preventive maintenance
carried out to avoid early failure.

 

 

 

Current training in design needs to concentrate
in what to do rather than what not to do. A similar situation exists in
training in construction techniques, where the craftsman is instructed how best
to undertake a particular operation but, to a lesser extent, in the dangers of
deviation from an accepted technique. Understanding of the likelihood of
defects through inadequate design or construction is taught implicitly rather
than explicitly. The level and nature of defects in building construction
currently encountered suggest that more guidance is required on the avoidance
of failures. A need is seen, too, for such guidance to be a positive part of a training
curriculum. It seems better to aim at identifying the principal defects and
their causes which, if wholly eliminated, would prevent the great majority of
the defects which currently occur, save occupants of buildings much annoyance
and discomfort, and reduce the national bill on maintenance and repair by
scores and, possibly, by hundreds, of millions of pounds annually.

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