Friday, November 15, 2019

The Biggest Cause Of Waste On Building Sites Construction Essay

The Biggest Cause Of Waste On Building Sites Construction Essay One of the major problems in the construction industry is the wastage of materials. The construction industry generates more waste than the household sector and can account for more than 50% of the deposited material in a typical landfill. Construction waste can be separated into three major categories: material, labour and machinery waste (Ekanayake and Ofori 2000). Material waste however is a greater concern as it is extremely expensive and is made up of non-renewable resources. According to H Lau (2008), large amounts of material wastes are generated from construction sites. Great amounts of costs on construction projects are directly increased through the wastage of materials. Construction waste is an international problem as In the UK construction waste results for more than 50% of waste deposited in a landfill (Ferguson et al. 1995) and according to Rogoff and Williams (1994) 29% of solid-waste in the USA consisted of construction waste. Levels of waste within the construction industry need to be reduced for environmental and financial reasons. The current unrestrained use of natural resources and the pollution levels resulting thereof are becoming unsustainable (Chong, Tang Larsen 2001) Waste management is a low project priority and there is a lack of appropriate resources and incentives to support it (Loosemore, 2001). Judging by the aforementioned statement one can already assume that waste management is something contractors are not too keen on. The minimising and disposal of waste has become one of the most significant environmental issues of recent years, especially as the total volume of available landfill is decreasing (Institute of civil engineers). A landfill can be defined as a method of solid waste disposal in which refuse is buried between layers of dirt with the aim to fill in or retain low-lying ground. One can clearly assume that sometime in the future landfill space will eventually run out. This is indeed a problem in Cape Town. The disposal of construction waste is becoming a major cost in construction projects. Many case studies have been done to monitor construction waste trends on construction sites and the impacts that it has on costs. In South Africa the construction industry generates an estimated 5 8 million tons of construction and demolition waste per annum. Over one million tonnes of building rubble reach landfill sites every year throughout the country (Macozoma, 2002). In order for contractors in the construction industry to be competitive, ways of minimising construction waste need to be addressed with benefits of lower construction costs and higher productivity. This can be beneficial to the contractor in terms of cost and it can assist in contractors doing their duties towards a good clean environment. Objectives of the study Aim of study: The aim of this research is to identify what is the major cause of materials wastage on site. Research Objectives: The main objective of this research is to find out what elements is causing wastage on construction projects. The research will be supported by a literature review showing the current wastage situation that the construction industry is faced with. Importance of the study According to Chang and Chen (1998) every business is started for earning profit. Waste has a negative impact on producing profit as it results in increasing expenses. One of this studies objectives is to investigate and recommend steps to eliminate wastage which will automatically reduce the companies expenses and therefore increase its profit. When materials are damaged and cannot be used for its intended purpose it is considered to be a waste. This leaves the material useless with no other alternative but to dispose of it. All this waste eventually adds to the already increasing negative statistics concerning construction waste. Many contractors fail to adopt a proper controlling procedure as they see it as an expensive and time consuming process (Illingworth Thain 1987). The approach has been that it is more efficient to allow losses to occur than to involve the use of extra resources to control them. Contractors require some sort of incentive to enable them to be more motivated when it comes to monitoring waste on site. 1.5 Research design and methodology The method of research to be used for this investigation will be in the form of qualitative and quantitative research. Qualitative data will be gathered from interviews taken to determine the nature of the problems with regards to construction waste and what contractors are doing to control it from competent staff in the building industry. A literature review will be done by gathering information from various textbooks, the Internet, web pages and journals etc relating to the research topic. All interviews will have pre-determined questions which were formulated before the interview, without the individual knowing about them, so as to effectively use the time. Quantitative data will also be obtained by sending out a questionnaire to various construction companies in Cape Town. The results will then be recorded and various graphs and charts will be drawn up to represent the data collection process. 2: Literature review 2.1 Construction waste It is important to understand the concept of construction waste. Listed below are definitions of waste. 2.1.1 Definitions: According to Mossman (2009) Material waste can be defined as anything that is not required to create value for the end-user. Waste can also be defined as an excessive use or carelessness of material (Chandler 1978). Construction and demolition waste means non-hazardous waste resulting from the construction, repair and demolition of structures. 2.1.2 Types of waste Construction and demolition waste can be categorised into five categories, namely roadwork material, excavated soil, demolition waste, site clearance waste and renovation waste (Alarcon 1995). It also results from natural disasters such as earthquakes and tornadoes. Construction and waste includes but is not limited to concrete, bricks, asphalt, glass, carpeting, roofing, site clearance, excavation material and site sweepings. Waste such as timber, plastics and steel should be recycled as they form majority of the waste material 2.1.2.1 Direct waste: According to Skoyles (1987) this type of waste is the physical loss of a material. It is the complete loss of materials which are damaged and cannot be repaired or used. Below are forms in which direct waste occurs: Deliveries waste comprises all loses in transit to the site, unloading and placing into the initial storage. Site storage and internal site transit waste comprise losses due to bad stacking and initial storage, including movement and unloading around the site to stack at the work place or placing into position. Conversion waste comprises losses due to cutting uneconomical shapes, e.g. timber and sheeted goods. Fixing waste comprises materials dropped, spoiled or discarded during the fixing operation. Cutting waste include losses caused by cutting materials to size and to irregular shapes. Application waste includes materials such as mortar for brickwork, paint spilled or dropped during application. Similarly, materials left in containers or cans that are not resealed. Mixed materials like mortar and plaster left to harden at the end of the working day. Waste due to the incorrect type or quality of materials. This includes waste stemming from materials wrongly specified, waste due to errors, particularly in the bills of quantities and specification. 2.1.2.2 Indirect waste: Indirect waste is distinguished from direct waste in that the materials are not usually lost physically only the payment or part or the whole of the value. Indirect waste is normally only a monetary lost and can be referred to as materials used for purposes other than that for which they were ordered (Skoyles 1987). Below are forms in which indirect waste occurs: Substitution, where materials are used for purposes other than those specified. Production waste, where materials are used in excess of those indicated or not clearly defined in contract documents, e.g. additional concrete in trenches, which are dug wider than was designed, because no appropriately sized digger bucket is available. Operational waste, where materials are used for temporary site work for which no quantity or other allowances have been made in the contract documentation, e.g. tower-crane bases, site paths, temporary protection. Negligent waste, where materials are used in addition to the amount required by the contract owing to the contractors own negligence 2.1.2.3 Natural waste: Natural wastes are wastes which cannot be avoided and is therefore inevitable. Cuttings required for tiles and timber and resulting in unusable material or off cuts are examples of natural waste. (Skoyles 1987) 2.1.3 Causes of building waste on site Waste is generally caused by a series of events and not due to a remote aspect (Skoyles and Hassey 1974). Guthrie (1998) mentions however that wastage of material can be directly involved to one of the following: damage and spillage, contamination, storage beyond expiry date, over supply, out of specification, theft and vandalism. There are many contributory factors and theses factors are outlined in the diagram below: Figure 2.1: the origin of waste (Department of Civil and Building Engineering) Low and Tan (1997) states that construction waste can be classified into seven types: Transportation and storage Over-production Delays Unnecessary processing Surplus inventory Unnecessary movement Defects Table 2.1 sources and causes of construction waste (Gavilan and Bernold 1994) Source Cause Design Error in contract documents Design Contract documents incomplete at commencement of construction Design Changes in design procurement Ordering error and over ordering procurement Suppliers error Materials handling Damaged during transportation to site Materials handling Inappropriate storage Operation Error by tradesmen or labourer Operation Equipment malfunction Operation Inclement weather Operation accidents Operation Damage caused by subsequent trades Operation Use of incorrect material Residual Conversion waste from cutting uneconomical shapes Residual Off cuts from cutting material to length Residual Over mixing of material due to lack of knowledge Residual Waste from application process Residual packaging Other Criminal waste due to damage or theft Other Lack of onsite materials control and waste management planning 2.1.3.1 Theft and vandalism 2.1.3.1.1 Theft According to Skoyles (1987) criminal activities cause waste. The construction industry in South Africa is constantly challenged with the high crime rate in our country and theft is an everlasting setback from staff on site to the public off site. Theft has a huge impact on time, money and productivity because material has to be reordered and more money has to be given out for the purchase of new material (K Brulliard 2005). Criminal waste is inevitable and the cost of extra security has an additional cost on the contract sum. Contractors must establish their own security measures like taking more caution and recording any irregular activities. 2.1.3.1.2 Vandalism The construction project is most vulnerable to vandalism during the finishing stages. Graffiti artist and children tend to play a big role in vandalism which ranges from breaking windows to spray painting freshly painted walls. Vandalism is an international problem, even occurring in the Soviet Union (Skoyles 1987). There are two types of vandalism namely: intentional and unintentional. Intentional vandalism is hard to prevent as these are people who get pleasure out of ruining other peoples property but boosting up security should sort out the issue. To prevent acts of unintentional vandalism tougher and stronger material should be used that resist damage like special paints and glazes to resist scratches (Skoyles 1987). 2.1.3.1.3 Principal points to control criminal waste Cause Preventative measures Minor items stolen Keep all valuable goods in lockable storage and keep a record of all materials withdrawn. Theft Control access to site and prohibit strangers from entering. Vandalism Make sure there is security during work and after work. Prevent items from being accessible which are vulnerable to vandalism. Trespass: By public Keep boundaries defined. By children Advise schools of how dangerous building sites are. By builder Ensure drawings and setting out are carefully checked near boundaries and make sure deliveries are supervised and always placed on site. Table 2.2 Skoyles (1987) As soon as graffiti is noticed it should be removed to prevent encouragement of further graffiti. After hour security should be hired to prevent any unauthorized entry. No Trespassing signs should be put up around the construction site to daunt unauthorized entry. 2.1.3.2 Sub-contractors Many main contractors are adopting a new attitude towards sub-contracting a large portion of their work so that their work load can be decreased. According to Costantino (2001) main contractors sub-contract a large portion of their work to cut down on the high overhead expenses which is needed to manage a large work force. There are two types of sub-contractors the first one is labour only sub-contractor. They are groups of artisans and labourers and are usually employed by the main contractor to undertake labour intensive work such as brickwork, plastering and formwork. The second category of sub-contractors performs specialist work on site such as the construction of piles and installation of escalators or lift systems (Wong, 1990). Sub-contractors are usually employed to provide labour only on a job. This type of sub-contractor is called a labour only sub-contractor as they will be providing labour and the main contractor will provide the material required. It is therefore imperative for the main contractor to have control over the sub-contractors usage of material and to encourage the sub-contractor to have a wasteful attitude. Since large portions of the main contractors work are being sub-contracted, sub-contractors are therefore to blame for wastage. Sub-contractors see waste minimization activities as an extra workload and are seemed to be irrelevant (Lingard et al. 2004). The main contractor is the principal player and must set a good example of waste minimisation by motivating an attitude which puts reuse and recycling in use (Ofori and Ekanayake, 2003). Material planning and waste control policies should be included in the invitation for sub-contracts to cover the main contractor from any risk caused from waste (Skoyles and Skoyles 1987). Disciplinary clauses should be inserted to prevent and discourage wastage from labour only sub-contractors. Wasted materials are wasted profits and waste concerns everyone involved from the client and contracts director to the sub-contractor and labourer. Providing adequate training for sub-contractors will improve their attitude to minimize waste and will lead to more efficient and productive waste minimization. The contractor will by incur a small expense from the training but will gain a large return as the construction process proceeds. 2.1.3.2.1 Most common causes of waste by sub-contractor and effect on building operations. Labour only sub-contractor 1 Waste of materials causes profit loss to main contractor 2 Waste causes delay to sub-contract operations 3 May become liable if penalizing clauses used Labour and material sub-contractor 1 Loss to business for material wasted 2 Delay and consequential waste to own and contractors work 3 Can add to waste accumulating on site and therefore adding to contractors waste 4 May be liable for penalizing clauses in sub-contract for consequential waste, particularly damage to other trades Table 2.3 Skoyles and Skoyles 1987 2.1.3.3 Design A building is designed without any consideration of the method of construction being used. The size of materials is not taken into consideration and a vast amount of wastage results from cutting and excess use of materials (Skoyles and Skoyles 1987). It is recommended that designers should prepare designs which have less potential to cause site waste (Ekanayake and Ofori 2000). One of the major contributors to waste is the change in design while construction has already commenced. It is therefore imperative for the parties involved in the construction and design to co-operate closely to avoid any unnecessary waste related to design issues (Ekanayake and Ofori 2000). Wasteful practice should start in the design stage already by specifying materials that will reduce the amount of wastage and also resist any harmful activities against vandalism and theft. Designers should educate themselves with the sizes and lengths materials come in so that unnecessary cuttings will not occur (Skoyles and Skoyles 1987). 2.1.3.4 Manufacturers Most of materials are manufactured in standard sizes and comes in standard packaging. Materials should be manufactured in such a manner that it is in favour of the contractor. A typical example is cement, this product comes in a 50kg bag which most labour find extremely tricky to handle. This product is extremely heavy and strenuous handling results in the packaging being damaged and the product being wasted. Suppliers should give the end users necessary knowledge on how to handle, store and transport their products (Skoyles and Skoyles 1987). Mehta (2008) states that a large amount of waste results directly from the packaging the material is stored in and more environmental friendly packaging should be used which can be used on site after the goods are unpacked. Materials are usually damaged when they are delivered because buyers do not state the requirements. When material is transported it should be protected against rain or dirt from the road. Careful checking should be taken when materials are delivered and any damaged goods should be reported immediately. Manufacturers can reduce waste by: Placing appropriate protection around materials. Sizes of bags of cement to made available for easier handling. Metal banded goods to be protected from the weather Delivery vehicles to be designed to guarantee that materials will be protected during transit. Loaded vehicles should Have less loose material delivered. 2.1.3.5 Storage and handling Skoyles (1978) identified that storage and handling were the major causes of waste. Majority of the labour in the construction industry are unskilled. Unskilled labour is available at abundance as the country is currently faced with a recession and people are desperate for work. The availability of this cheap unskilled labour has a major impact on construction wastage. Poor workmanship and incorrect use of tools are key factors which contribute to wastage. Skilled tradesmen are less cautious about wastage as they can rely on the unskilled labour to clean up after them. Proper site supervision should be instituted at all construction sites to encourage workers to minimize wastage. Workers should be trained to make use of building materials effectively and efficiently. A well trained employee should be given the responsibility of keeping control of all materials. Storage facilities should be well managed and correct inventory list must constantly be attended to. The location of the storage area is vital to avoid double handling and travelling long distances to the place of work. There should be sufficient space at storage areas to accommodate for all the materials. Expensive materials should be stored in a lockable room to prevent theft and material should be stored in such a manner to prevent any damage. Material with a high value should not be stored on the job site any longer than necessary. 2.1.3.6 Delivery of materials All deliveries should be thoroughly checked for any shortages or damages. It is important for deliveries to be properly planned to reduce the risk of materials laying around that will only be used in the future. Contractors should make use of appropriate material delivery planning systems. Copies of the schedules should be kept on site to assist site management in the control of materials. Proper material delivery management will eliminate double handling and reduce wastage dramatically. Expensive materials should be delivered only when it is required on site. 2.1.3.7 Site security Access points to the site should always be locked and controlled. All access points should have gates so that it can be locked after hours. There should always be someone monitoring the access points to restrict any unauthorised entry. Lighting the site is very useful. Thieves are generally more comfortable in the dark and by lighting up the site the public will be able to see if any criminal activities are taking place A good fenced site will reduce the risk of theft and vandalism dramatically. Barb wire on top of the fence will secure the site even further. 2.1.4 Summary of literature review It is inevitable for a Construction company to produce waste. Identifying and categorizing the types and causes of waste help in minimization. It is important to enlist the cooperation of all parties involved in the construction project because they are the parties using the construction materials. Through proper planning and control, material wastage can be minimized without compromising on quality and time of completion. 2.2 Construction waste management 2.2.1 Introduction to waste management In terms of Schedule 5B of the Constitution of South Africa (Act 108 of 1996), waste management is a local government proficiency that must be executed to protect human and environmental health (Constitution, S.24). Macozoma (2006) stated that 40% of a countrys waste is contributed by the construction industry and 15% of materials purchased ends up as waste. Waste dumping has huge effects like filling landfills and damaging the environment. It is vital for construction companies to get involved with waste management so that pollution levels, natural resources and energy can be reduced. The key component in waste management is waste minimisation (WBDG 2010). The definition of waste minimisation is: any activity that can prevent the amount, supply and environmental impact of waste (City of Cape Town 2010). The following are benefits from waste minimisation (Camm and Nuttall 1995): Reducing the amount of landfill space Saving natural resources Saving energy Minimizing pollution 2.2.2 What is a waste management plan? According to Macozoma (2002) it is a plan that gives the guidelines and conditions to how waste should be handled and managed on site. Waste management should not only be the contractors responsibility but everyone involved in the project. A typical waste management plan will contain the following fundamentals: Waste management goals Waste prevention strategies Waste salvage strategies Material storage strategies Recycling methods A waste audit Waste disposal options Waste handling requirements Transportation requirements The following are benefits from good waste management practice (Clacksweb 2010): Decrease in disposal costs Decrease in waste transportation costs Increase in the reuse of materials Decrease in levels of material wastage 2.2.3 Why construction wastes management? The following are answers generated from Oikos (2010) 2.2.3.1 Cost By re-using materials you are cutting down cost by not purchasing new materials and you are therefore increasing your profits. 2.2.3.2 Efficiency Material should be salvaged to prevent ordering of new materials. 2.2.3.3 Resource Conservation Contractors can conserve natural resources by recycling their wastage materials. 2.2.3.4 Liability Contractors should take responsibility by getting rid of their waste through legal sources 2.2.3.5 Marketing Contractors who make use of waste management planning will have a positive situation in the market. 2.2.4 Summary of literature review Construction waste management planning is vital to the construction industry and to the environment. By applying waste manageable construction pollution levels will drop and contractors will reap the benefit of producing larger profits. South Africa is a growing country and should follow first world countries by adapting to waste management. 3: Fieldwork 3.1 Introduction The design of the data collection was undertaken in two parts. In Part one a questionnaire was drawn up based on the literature review and part in part two personal interviews were done to establish further information in concluding this research. 3.2 Questionnaire A questionnaire was drawn up relating to Table 1.1 sources and causes of construction waste (Gavilan and Bernold 1994). The questionnaire had 15 short questions which had to be rated on a scale of one to five. One was were the person strongly agreed and five was were the person strongly disagreed. The person who under took the questionnaire had to state their job title in order to get results from competent staff. The questionnaires were sent via email to 25 building companies in Cape Town out of the 25 companies only 22 responded. The data is therefore a representation of only 22 companies opposed to 25. (Refer to appendix A for copy of the questionnaire) 3.2.1 Questionnaire response 22/25*100=88% response to questionnaire The response received is more than sufficient. A failure to respond rate was targeted at 20% and an actual failure to respond rate of 12% was achieved. 3.2.2 Position of Respondents who under took the questionnaire This was vital because the questionnaire was designed for competent staff to fill out. Chart 3.2 Respondents positions According to the results received all the questionnaires were filled out by competent staff and all the questionnaires can be used for the data collection process. Quantity surveyors: 9/22*100=41% Site managers: 7/22*100=32% Contracts manager 2/22*100=9% Buyer: 2/22*100=9% Contracts director: 1/22*100=4.5% Foreman: 1/22*100=4.5% 3.2.3 Data analysis Chart 3.3 Survey response Table 3.1 Data recorded 1-strongly agree 2-agree 3-neutral 4-disagree 5-strongly disagree question 1 16 4 2 question 2 15 2 3 2 question 3 4 8 2 6 2 question 4 11 1 7 2 1 question 5 12 6 4 question 6 2 6 12 2 question 7 2 9 9 2 question 8 4 2 6 7 3 question 9 4 10 6 2 question 10 1 9 7 5 question 11 2 4 7 8 1 question 12 3 5 11 3 question 13 7 7 8 question 14 4 3 5 6 4 question 15 2 3 14 3 3.2.3.1 Analysis of questions Question 1 73% of the respondents felt that errors in the contract documents caused wastage. Question 2 68% of the respondents strongly agreed that a variation in the contract causes wastage. Question 3 Only 54% of the respondents thought that a lack of waste management planning causes wastage. Question 4 50% of the respondents believed sub-contractors have a major influence on wastage. Question 5 0% of the respondents disagreed that cutting of standard material to sizes causes waste. Question 6 54% of the respondents had a neutral feeling that vandalism and theft influences waste. Question 7 50% of the respondents believed proper storage has an effect on waste. Question 8 45% of the respondents disagreed that security could minimize waste. Question 9 63% of the respondents believed unskilled labour influences waste. Question 10 54% of the respondents believed that are not any waste caused from the transportation of material from the suppliers. Question 11 40% of the respondents disagreed that waste is caused due to machinery malfunctioning. Question 12 50% of the respondents had a neutral feeling that waste could be resulted from the lack of waste minimization training on site. Question 13 The sum of 5% of the respondents felt that over ordering influenced waste. Question 14 45% of the respondents believed over production causes waste. Question 15 63% of the respondents had a neutral feeling to waste minimization being of any importance. 3.2.3.2 Ranking of questions A ranking of the questions was done in order to clearly illustrate the main cause of waste according to the questionnaire. Neutral answers were ignored and strongly agree and agree were joined together to form yes and strongly disagree and disagree were joined together to form no. Table 3.2 Ranking of questions yes no total Question 1 20 0 20 Question 5 18 0 18 Question 2 17 2 19 Question 9 14 2 16 Question 3 12 8 20 Question 4 12 <

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