In construction sites, most of manual works require at least two workers cooperating each other to complete a task properly. If it is possible to make a single worker carry out these kinds of tasks with the assistance of a robot, the overall construction efficiency can be increased. This study deals with the application of a supernumerary robotic limb (SRL) to the construction tasks. In this paper, two typical construction tasks that can be improved by supports of SRL are considered. One includes the tasks that require a worker to hold an object like a panel in a desired position with an appropriate force while the other worker finishes main processes. The other contains moving or holding construction materials which are difficult to be held by one hand not because of its weight but because of its shape or size. For the first case, the SRL that sits on shoulder or waist with position based force controller can be utilized. For the second case, the robotic limb should be able to assist the worker in holding and balancing the object while the one carries it with one hand. As for the case studies, two types of extra robotic limbs were used. One was mounted on the shoulder and the other was attached on the wrist. Both types were applied in the situation of ceiling works in different ways. From many experiments, it was shown that the SRL can be effectively utilized in construction sites for diverse works.