When considering polished concrete or polished micro concrete screed the first question should be are you doing it for aesthetics’ or durability. The polishing system has over the years been fine tuned to produce a floor finish that is EASY TO CLEAN – LIGHT REFLECTIVE – DURABLE – HARD WEARING AND ENVIROMENTLY FRIENDLY.
Other benefits are that the surface appears MODERN – CRISP AND CLEAN
After the polishing process the floor will be at the level it was before less approximately 2mm. Dependant on the slopes in the original floor will depend on how light reflects and how flat the surface appears. We recommend overhead lighting where possible.
The surface appearance will differ in appearance dependant on aggregate placement. As concrete is discharged the aggregates and fines create an intertwined matrix with large and small particles mixed together, due to this there may be some areas with larger aggregates and areas with large amounts of smaller aggregates. Also when laying the concrete some particles are pushed deeper into the surface. This is why aggregate displacement happens, and why we do not guarantee or infer in any part that the aggregates in the surface will be of an even size or spread. In some cases major changes can be apparent from 0.5mm – 20mm aggregates in close proximity. Should a guaranteed aggregate spread be required, we would suggest a dry shake micro aggregate surface be considered.
Shadowing through the surface can sometimes be apparent, these can be a result of the process used to install the concrete. As above the concrete aggregates / matrix can be displaced, this maybe a foot passing through the concrete, a straight edge used for ruling of or any other object that has passed over or through the matrix. We call these shadows as they are visible though the surface yet cannot be felt with the hand. Many of our customers feel these add character and consider them a unique feature within their floor.
Concrete when laid is under a great amount of stress caused by its internal drying process. We best describe this as a large area of moist matter dispersing water very quickly within the first 24 – 48 hours of install. The result is that the concrete shrinks as it releases the water. We know from testing that as the water is released the concrete shrinks from the outer edges inward and that if left alone cracks / fractures would appear at intervals of approximately 6m or at 1.5 times the width of the panel. Every effort is made to second guess where these cracks / fractures will occur and joints are installed to relive the stresses. Any fractures that may still appear are filled using fillers during the polishing process. Whilst the fractures are filled they can remain evident in the surface.
Stresses can also happed across the surface the can be caused through temperature change, breezes over the surface or differential hydrating. The result is surface shrinkage which appears as crazing within the surface. In some cases depending on the depth these are removed in the polishing process, however in other cases these can run much deeper and remain visible at the surface. These are filled during the polishing process and are approximately 0.4 – 0.8mm wide.
All of the above we consider to be aesthetics, none of them detract from the floors structural integrity or its durability. The floor would still provide an easy to clean, light reflective, hard wearing and environmentally friendly surface giving a modern crisp look that will last for years.
To provide a long lasting finish to the new polished concrete please ensure the maintenance regime is followed.