Abstract:
Construction materials are among the most important resources in a home building project. Thus, their acquisition, purchase, and allocation must be carefully carried out in order for a project to run smoothly and be completed as planned. This study aimed to examine the processes of acquiring, purchasing, and transporting construction materials to ensure that they would comply with a project plan. The research also investigated how to effectively store construction materials, control their use, and eliminate waste. The sample was comprised of fifteen general members of the Home Builders Association selected using a purposive sampling technique. The data were collected from interviews with the respondents and related documents dealing with the concepts, principles, and methods of construction materials management.
The results showed that the processes of managing construction materials depended on two factors: 1) the method of construction and 2) personnel assignment. The method of construction could be classified into two types: the cast-in-place method and the prefabrication method. They differ mainly in terms of the processes of acquiring and storing construction materials. The cast-in-place method is more complicated as it requires the calculation of the amounts of steel, wood, concrete, sand, and stone to be used as well as effective preparation of the site for storing the materials. The prefabrication method, in contrast, is easier and faster since all assemblies are ready for use right from the factories. In terms of personnel assignment, two methods were identified: 1) insourcing and 2) outsourcing. The latter could be further subdivided into one in which the contractors acquire construction materials on their own (Type 1 contractors) and one in which the sample organizations supply construction materials to the contractors (Type 2 contractors). The findings revealed that insourcing involved internal construction materials management from the beginning to the completion of a project, thus requiring staff with expertise in controlling the use of materials. Outsourcing, on the other hand, placed all the burden pertaining to the management of construction materials on the contractors.
As regards construction materials management, the respondents were found to fall into four groups, depending on their situations and limitations. The first one was comprised of those using the cast-in-place method while employing insourcing in their project operations for both structural and architectural work. The home builders using the cast-in-place method while employing outsourcing (Type 1 or 2 contractors) in their project operations for both structural and architectural work constituted the second group. The third group were the home builders using the cast-in-place method while employing only Type 2 contractors. The last group was made up of those using the prefabrication method while employing insourcing only for structural work and outsourcing (Type 1 or 2 contractors) only for architectural work.