Most concrete shrinks while it sets, cures and gains strength. 

This is because water in the mix rises to the surface and evaporates – therefore the concrete is losing volume. As the concrete has not yet gained any strength, this shrinkage can cause unsightly cracking. Slabs, driveways and footpaths are vulnerable as these have large exposed surfaces. 

When concreting in dry, hot weather, when it is windy or the humidity is low, it is important to prevent early loss of water from the concrete. Hot days, wind and low humidity in combination or separately can cause these cracks and reduce your working time.

In these conditions, it is important to take precautions when handling, placing, compacting, finishing and curing concrete. This is very important during the spring and summer months, but it can happen at any time of year.