How To Calculate Waste Percentage In Construction – In order to calculate waste percentage in construction, first identify the total weight or volume of waste generated from the project. Then, divide this number by the total weight or volume of all construction materials used. Multiply this result by 100 to obtain the waste percentage.
The calculation can be measured using four methods; percentage of material purchase, % of material required by design, kg/m2 of gross floor area and m3/m2 of gross floor. The method of survey is done by the composition of volume and mass and the Waste Generation Rates is found between 3.275 – 8.791 kg/m2.
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How to estimate the amount of waste in a construction project?
ESTIMATION OF BUILDING WASTE FROM THE CONSTRUCTION ESTIMATION OF BUILDING WASTE FROM THE CONSTRUCTION In this article, you can learn how to calculate the amount of construction waste that will be generated from construction projects. Based on this information, the direct cost of material waste and the consequent cost of waste disposal and treatment, for example, sorting can be calculated in order to control costs.1.
- CONCRETE WASTE The amount of concrete residue, for example, can be estimated by knowing the level of material waste from the concrete.
- Recent research indicates that the average level of waste is approximately 4%, which is considered the norm for the concrete trade in this guide.
- However, it could be reduced to 3% if careful ordering and handling of the material are applied.
The amount of waste can be estimated according to:,2. WASTE FROM BLOCKWORK AND BRICKWORK The granular waste generated by block and brickwork is 10% of the quantity of the work required in the construction project. The estimate can be calculated as follows:,3.
- WASTE FROM SCREEDING AND PLASTERING A higher wastage of 15% is given as the norm since these trades are difficult to control.
- The estimate can be calculated according to:,4.
- WASTE FROM TIMBER FORMWORK The Timber formwork is assumed to have been used at least 12 times before being discarded.
- Wood residues can be estimated according to:,5.
PACKAGING WASTE Construction contractors have little control over the amount of packaging waste produced, which is estimated at 5% of the volume of materials requiring packaging, therefore, The percentage wastage by different trades for public housing projects and private residential buildings are shown in Tables 1 and 2 for reference.
| TABLE 1 |
Tables 2 : ESTIMATION OF BUILDING WASTE FROM THE CONSTRUCTION
How to calculate wastage of cement and rebars in construction?
1.Calculation of the wastage of various materials during the estimation stage. Usually, 5% of wastage is considered on the quantity of cement whereas for the Rebars around 2.5% wastage is quite appropriate to consider.2.Determining the actual wastage of cement and Rebars in the entire construction. (Post construction ).
What is the allowable percentage of wastages in construction works?
The material wastage is the major problem in construction that affects the project cost significantly. Some material wastages like bricks that could be reusable for brick bat coba, and some can’t be reused again in construction. However, we can not completely stop the wastages from happening while working, but we can control it. Every quantity surveyor will add some permissible wastages while estimating materials to know the construction cost. But it does not mean that we could waste up to those allowable limits. These wastages are not only added for workmanship but also for environmental factors. The construction works are measured as per the IS code 1200, but the allowable percentage of wastages has not explained anywhere. There are no IS codes for estimating the wastages. The allowable wastages for major construction materials have been listed below for estimation as per practical experience.
What are the is codes for estimating the wastages?
The material wastage is the major problem in construction that affects the project cost significantly. Some material wastages like bricks that could be reusable for brick bat coba, and some can’t be reused again in construction. However, we can not completely stop the wastages from happening while working, but we can control it. Every quantity surveyor will add some permissible wastages while estimating materials to know the construction cost. But it does not mean that we could waste up to those allowable limits. These wastages are not only added for workmanship but also for environmental factors. The construction works are measured as per the IS code 1200, but the allowable percentage of wastages has not explained anywhere. There are no IS codes for estimating the wastages. The allowable wastages for major construction materials have been listed below for estimation as per practical experience.
