A surface polish is one of the most difficult finishes for any polished concrete contractor to achieve, so it is important we set your expectations from the beginning to get the best possible outcome. The single most important factor is your slab. You will need a great concreter and the right concrete, we recommend a 40 MPa mix, finished to a Class A standard with little-to-no undulations in the floor.
We have a very important surface polish concrete pour guide that is essential for your concreter and builder to follow, just ask our friendly office staff for a copy to pass on to your builder, architect and concreter. If the slab is done right, we have the best chance of achieving a consistent no-stone-exposure "burnished" look with minimal imperfections. If the concrete is not poured to specification, is very soft, or has other issues, some of the outcomes below are what you might end up with.
A surface polish is not a finish we would normally recommend for residential projects, unless it's an architecturally burnished slab. If your concrete isn't completely flat, we recommend moving to a finish that involves some grinding so the high and low spots can be removed, a surface polish does no grinding and cannot remove them.
Please note, we are not responsible for the standard of your slab and cannot guarantee the finish. All of the outcomes below are possible and are not considered a defect of the polished concrete floor, because they are caused by the concrete itself, the curing or the placement, all out of OzGrind's control.
Low spots may not be reached by the machine and will likely leave the concrete crust in place. These areas look and feel different to the rest of the floor, lighter in colour, and dusty and untouched by the polishing machine.
Where there are high spots from undulations and your concrete is soft, these areas may achieve some very slight stone exposure.
Imperfections and colour variations (lighter and darker areas) from the troweling and burnishing process will still be visible, as we do no grinding and cannot remove them. Grinding further would mean additional cost and would create stone exposure. Expect screed marks, helicopter marks, boot prints and light patches.
If the slab is undulated and uneven, these undulations will remain completely visible in the surface after completion. The higher your gloss level, the more visible the undulations become.
Recycled water used in the slab mix can cause browning discolouration that may be visible in the finish. Staining left by builders or other trades before we arrive will not be removed by the surface polishing process and will remain visible afterwards.
Because more cementitious surface is visible with this process, swirls, strikes or scratches around low spots and gouged or chipped areas can be more noticeable, especially on a lower-MPa slab.
Holes and blow-outs will not be filled or polished. With no grinding done, repair compound applied to shallow holes often will not stay in and plucks back out when the machine passes over it. No filling or repair is allowed for in surface polish quotes, so additional charges may apply, with no guarantee the repairs will hold or all get filled. Any repairs requested may require grinding to remove excess compound, resulting in stone exposure, and the compound will be a visibly different colour to the concrete.
Slab edges are usually finished by the concreter by hand, so they can have a different, lighter appearance and may end up with some stone exposure due to the concreter's finishing methods not closing over the area as much as a power trowel or helicopter.
The way your concrete slab looks the day we arrive is the exact way it will look when we finish, it will simply feel smoother and look glossier depending on the level of sheen you choose.
If you have any questions in relation to this document, please do not hesitate to contact our friendly office staff on 07 3177 3367 or enquiries@ozgrind.com.au.
By signing below I confirm that I understand OzGrind is not responsible for the standard of my slab and cannot guarantee the surface polish finish. I accept that the outcomes described above are possible and are not considered a defect of the polished concrete floor. I confirm I have received, read and understood all content in this document and the important terms & conditions in my quote.
Tell us about your space and whether your slab is new or existing. We will come back within 48 hours with honest advice and a no-obligation quote.
