The Handyman's Guide to Concreting at Home
 
 

If you want a smoother finish than the screeded surface, use a wood float.
“Floating” agitates the surface, compacts the material, and brings enough mortar to the surface to fill the voids. Use the flat with some light pressure and tilted slightly upwards into the direction you are pushing it. After floating, round off the edges with an edging tool.

A rough texture can also be obtained with the wood float by swirling the concrete, or by drawing a broom or a brush over the surface.

A steel trowel finish may be used on such surfaces as garage floors, but will become slippery when wet. Such a finish is not recommended for external driveways, patios, etc.

If a very smooth finish is required, use a steel trowel after the concrete has become quite stiff, taking care to avoid bringing excess water and fine material to the surface. Start trowelling as soon as the “shiny water sheen” disappears, but while the concrete still looks damp. Do final edging at this time. You can do final hard trowelling when the concrete is nearly hard.



The time span between the screeding and finishing process varies between summer and winter. On a hot day, the time could be as little as an hour (in extreme cases, less), but on a cold day as much as several hours. Be patient - the water sheen is your guide. It is good practice - especially in winter - to start your concreting early in the morning.

Under no circumstances should you attempt to trowel the concrete while water is lying on the surface. This will make the surface weak, with dusting or powdering likely to occur.

Where sections greater than three metres long are being placed (such as a driveway or long path), evenly divided grooves should be made across the concrete surface with the grooving tool. The distance between grooves should be no greater than three metres. The grooves aid in the prevention of concrete cracking. Use the flat side of the screed board as a support and guide when making the grooves.