Trowelling:

The last operation of finishing is known as trowelling.

Trowelling is performed while here a smooth and dense surface is desired. Trowelling should be delayed as far as probable. In most of the cases, trowelling is performed although the concrete is too plastic and soft. At this stage, excessive trowelling will cause crazing and result in a surface having less wear resistance. The significant point is the period at that the trowelling is done and the pressure used through person responsible for the last operation of finishing. Finishing is always carried out along with the trowel and the float. After floating surface should be permitted to dry and stiffen till all the excess water has disappeared.

Trowelling should be completed after water has evaporated from the concrete surface. The Spreading dry cement on a wet concrete surface to absorb excess water is not a good practice. The occurrence like wet surfaces should be prevented. The finishing procedure should be delayed if such spots occur.

A gap of sometime should be left among successive trowellings in order to allow concrete to increase its set. Firstly, an older trowel is preferred to a new trowel. Trowel blade should be remaining as flat against the surface as probable.

Power float or power trowels are commonly used in finishing large surface area such as aircraft hangars or factory floors and is not economical for small areas like as flats or dwelling houses. In during trowelling, cement should not be spread, as it is dangerous and liable to generate a neat cement skin, which peels off after some time. Trowelling along with power trowels should be delayed till the concrete becomes firm.

Trowelling should be finished on the similar day as the laying operation. Artificial drying could be extremely effective by laying cotton sheets on the floor and covering them with 2.5 cm to 5 cm of dry cement. The water is absorbed through the sheets which could be lifted afterwards say 10 or 15 minutes and after this trowelling could proceed for finishing the concrete surface.