Polished Concrete: Realistic Expectations and A World of Possibilities
Polished concrete is cost effective, environmentally healthy and extremely durable. The flexibility of it goes beyond what people have ever imagined. There is a catch though. It is very important to hire professionals when pouring the concrete. It is this first step that will pave the way (no pun intended) and set what your floor will look like for the entirety of its life. I don’t know if you have seen ancient ruins like the coliseum, they are really old, still standing and made of concrete.
Example of “bad” cement floors that make it difficult to have a beautiful final product.
We have put together this list so you can set some realistic expectations for your polished concrete floor. Expectations to keep in mind:
Discoloration of Polished Concrete: There are many factors that can contribute to the problem of polished concrete floor discoloration. Inconsistency in materials or supplies used, weather conditions or the quality of the workmanship provided by the crew on the project.
The best way to prevent color variations is clear communication between the owner, their representative or general contractor of what is expected in order to avoid misunderstandings. Communicate with the batch plant about the mix used to ensure the identical mix is used onsite and that the crew members use the identical placement methods.
Poor Edge Finishing: When concrete is placed, edges must receive the same attention as the rest of the floor or it will result in poor edge finishing.
The best way to prevent poor edge finishing is to include your concrete finisher in the beginning stages of construction. This way, we can make sure the final product meets your expectations. Otherwise, not much can be done even if hand ground and polished around the wall edges since light discoloration can be the result.
Ghosting: When VCT or tile has to be removed from your floor before it can be transformed into a beautiful polished concrete floor, a grid pattern is likely to remain. This is called ghosting or shadowing in the polished concrete world. It also happens if glue from tape remains on the floor or acidic contaminants are spilt on the floor and not cleaned properly before grinding and polishing.
The best way to prevent ghosting is to make sure that nothing is on the floor during the first 30-day curing period and never tape directly on the concrete before or after sealing. If there was tape placed or a containment is present, use a solvent or chemical cleaner to remove the residue.
Uneven Hydration: When concrete is curing, water escapes the slab at the surface. If items are placed on the concrete during curing it can result in hydration marks that will eventually dry but, it could take a year or more. This could also cause discoloration.
The best way to prevent uneven hydration is to not leave any buckets, boards or other materials on the concrete floor during the curing process.
Footprints and Foreign Debris: If not enough time is given for a concrete slab to dry and the concrete is given the green light to be finished, footprints or other items like leaves, cigarettes or pine leaves may fall and be left in the slab. Once the floor is ground and polished, the debris can be seen and must be removed and patched before the floor is considered finished.
The best way to prevent footprints and foreign materials left in the concrete and make sure it is done right the first time is to keep the area clean and communication between the company pouring the concrete and the company that finished the concrete floor. Concreate also uses ACTECH Go Early Technology products that allow for fast curing to reduce downtime on your flooring projects.
Varying Aggregate Exposure: If the concrete has not been professionally poured, it will likely have some dips that will not be able to ground down evenly when polished. It will cause unevenness in your floor and uneven aggregate exposure.
The best way to prevent differing aggregate exposure on your polished concrete floor is to make sure the concrete has been poured to a floor flatness level of 40 or higher. Secondly, communicate with your contractor as to your expectations for your facilities floor.
Wavy Floor: The most common issue with polished concrete floors is a wavy slab. It is very difficult to tell just by looking at the floor but it will stand out once polished. You will find uneven aggregate exposure which may not be your desired final result.
The best way to prevent differing aggregate exposure on your polished concrete floor is to make sure the concrete has been poured to a floor flatness level of 40 or higher. Communication between the owner and the concrete polishing company should clarify any expectations.
The bottom line is that communication will help clarify what to expect from your polished concrete floor. That being said, there are endless possibilities when polishing your concrete floor that every time you walk on it will leave you wanting to polish all your concrete floors.