In our opinion the best route to a perfect polished concrete floor is to involve professionals right from the start. Your main contractor will install the sub floor – a slab of concrete with reinforcing bars, plus insulation beneath – ready for the specialist concrete contractor to install his, usually 100mm thick, concrete floor on top at a later date.
After your concrete contractor installs the concrete slab, they should take care not to walk through the mix as this could cause sandy patches at a later stage as their footfall could push down the aggregate. Power floating will be needed to produce a smooth, level, surface but when placing concrete destined to become a polished floor extra special care and attention needs to be paid to the perimeters. These can often be botched in normal concrete floor situations, even with power floating and hand troweling.
The leveling, floating and finishing of the concrete needs this high attention to detail because when the surface comes to be grinded and polished. If the above precautions are not taken then it may not be possible to provide the floor finish you requested. We are happy to advise concrete contractors / builders / engineers before and during the process so to mitigate any potential concerns they have.
Your concrete installer will advise how to prevent, as far as possible, any settlement cracks that under normal circumstances wouldn’t matter but are now on public view. Such cracks can appear many months or even years after installation so there has to be a plan for how to deal with these. A concrete expansion joint or control joint is a gap which allows the concrete to expand and contract as/when the temperature changes. It forms a break between the concrete and other parts of a structure to allow movement without causing stress, which can lead to cracking. These control joints are cut by the concrete installer and filled at a later stage by a choice of materials such as Mastic, Brass & Aluminum.
Once installed and cured, the concrete should be well protected while other construction takes place. Pieces of scaffolding, for example, dropped on to the surface can cause blemishes that are near impossible to remedy. Of course, once the concrete is polished and ‘finished’ it has to be lovingly protected as if it were a timber floor. In this regard it’s vital to get the surface protected so decorating and other liquid building materials don’t stain it.