Ground bearing floor slabs

The process of power floating and steel trowelling is common in industrial buildings and retail warehouses where, for operational and cost reasons, the provision of a sand and cement screed is undesirable. Sometimes termed panning, the process involves the use of a machine fitted with rotary paddle blades. Some large machines are ride-on, other types are walk-behind - the latter impart less energy to the floor than the ride-on types.

The rotation of the blades embeds aggregate particles just beneath the surface, removes slight imperfections, humps, and voids, and compacts the mortar at the surface in preparation for additional finishing operations. Sometimes swirl marks from the rotating blades can be seen in the finished surface. If the surface is overworked during panning, a burnished appearance can result. Where a smooth, hard, dense surface is desired, floating is usually followed by steel troweling.

Careful quality control is needed to achieve a good power floated floor, the process relies on the skill of the float operatives and appropriate judgment as to the optimum time after laying as well as various other factors.

Problems develop when the floor is power floated too early and consequently overworked.