An Empirical Determination Of Labour Output For Painting In The Nigerian Construction Industry

Research has shown that construction labour output is crucial to the success of construction projects. However, existing labour output used for the preparation of construction estimates in Nigeria are outputs derived from untested experiences. The focus of this study is to use the work study approach to empirically establish labour output for painting activities for the Nigeria construction industry using the classification in the BESMM3 as a guide. The procedure adopted field survey involving work measurement to observe and measure operatives output. Data were collected from on-going construction works and analysed using descriptive and regression analysis. The analysis carried out established general average output value per day as follows; painting of general surfaces of walls, girth greater than 300mm with (textured paint, 128.53m2; emulsion paint, 81.07m2; gloss paint, 72.58m2). Painting of general surfaces of walls, girth less than or equal to 300mm with (gloss paint 211.10m, emulsion paint 277.59m); Painting of general surfaces of ceiling soffit, girth greater than 300mm (emulsion paint 85.31m2).The findings in this study revealed a higher output per day for painting of general surfaces of walls, girth greater than 300mm using (textured paint, 128m2). This study shows that different items of work in painting trade have various measuring units and also various labour outputs. The results of the analysis suggested that mode of employment, qualification of workers, temperature of the work environment, period of observation and experience of the operatives affect output of workers to varying degrees based on the location of application of the paint and the unit of measurement of the work items. This study has recommended that the established output should serve as an effective baseline for efficient estimating process and be in compliance with the BESMM requirements.

Estimating is one of the key fundamental functions of the Quantity Surveyor and accurate estimates are very vital to clients when making decisions therefore, clients expect useful and objective information from estimators. Cost estimates provide a useful basis for budgetary planning and cost control for construction projects. Garret (2006) reported that the sustainability and success of the construction industry depends greatly on the level of accuracy in project cost estimates.

Estimating the costs of construction works involves the multiplication of unit rates and the measured quantities in the Bill of Quantities. The calculation of the unit rates for the individual measured items in the Bill of Quantities requires the collation of current cost information for materials, labour, plants, profit and overhead (Ashworth, 2002). The estimation of the cost of materials, plant, overhead and profit has never been a point of contention because they involve the quantitative estimation of the cost values for plants, profit and overheads while market survey are carryout for materials prices and are the basis for the material cost estimation (Ashworth, 2002). Labour pricing is usually done on the basis of output constants collected on each trade (Ayeni, 1999). It is important that cost estimates have clear indications of the level of information reliability.