What are polished concrete floors?

Polished concrete floors are a finished floor system that is created by running a series of diamond tooling passes and product applications to an existing concrete floor. Polished concrete can be installed on most types of concrete floors; some of the floors are new concrete, others have been around for many years and have been underneath other types of flooring systems like carpet, tile, vinyl or wood.  One of the biggest items to be aware of with polished concrete is that the existing concrete will play a very large role in the finished look after polishing. The polishing process doesn’t change what is already in place, it only enhances the beauty and durability. The best comparison is to imagine a rough unfinished wood floor and then hiring somebody to come in and finish/sand/clearcoat that wood. If there is wood grain patterns or knots in certain areas they will remain but have a more finished appearance. Polished concrete is very similar, the biggest difference is some of these characteristics will not be known until after the initial cutting pass is complete and the aggregate below is exposed. The placement and finishing techniques used to pour and finish the concrete when its initially installed could play a large role in the outcome of a polished concrete floor. These characteristics are part of the beauty of polished concrete, every floor is different!

​The first step is to remove the existing flooring, sealers, residue or adhesive. Once this is complete, the next step is to repair any cracks or chips; this is typically done with a 2-part resin repair product mixed in with some concrete dust from the floor to try and match it as close as possible. Control joints are typically filled in with a flexible polyurea joint filler and shaved smooth with the floor. Joint filler comes in a variety of colors to either match closely or something complimentary to the finished floor. Some of our customers like the control joints to stand out with a contrasting color, others prefer them to blend in as close as possible. Control joints are “planned cracks” and should only be filled in with a flexible material so they don’t inhibit future cracking or movement. Filling control joints also keeps them from collecting dirt and debris, making the floor easier to clean.
Once the floor is down to bare concrete and repairs are complete its time to start grinding! The hardness and condition of the floor may determining what bond and grit diamond tooling is used; we generally start our grinding using a 25, 50 or 60 grit metal bond diamond tooling. The initial cut of the floor will likely expose some of the aggregate below. The majority of our floors are a “sand” finish and only expose a fine aggregate. Floors that require a larger aggregate exposure may require additional passes or different tooling to create that appearance.
Once the initial grinding phase is complete we generally apply a resin type grout to the entire floor, this fills in most of the microscopic pinholes and hairline cracks. The resin is troweled over the entire floor and generally cures within an hour. The majority of this product is removed with the next grinding pass, the pinholes and cracks are now filled.  This grouting process adds an additional step to the installation but leaves a much better finished product.
Applying a densifier to the floor hardens the concrete, makes it easier to polish, and helps the floor resist stains and wear and tear. The densifier is applied generously to the floor and allowed to soak in for a period of time. After the densifier is applied, resin bond diamond tooling is used up to an 800 or 1500 grit polish to finish off the floor. Some floors may be polished as high as 3000 grit but this is less common.  Burnishing the floor at completion removes any residue left from the resin tooling and gives the floor a clean finished appearance. Adding a stain guard or stain repellant can help with the longevity of floors and create a more even look, stain guards will also help. Stain guards may need to be reapplied over time if they are subject to high levels of traffic.
 
Cleaning polished concrete floors requires no special equipment or products unless your project is very large. Using a non abrasive pad or mop and neutral PH cleaner is all that is required. Larger floors and commercial spaces may have walk behind scrubbers or floor cleaners fitted with the correct pads and cleaning chemicals.
Contact Master Concrete Company for all of your concrete grinding & polishing needs via our website www.MasterConcreteMN.com email [email protected] or call us 612-615-1811. 

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