Frequently Asked Questions

We recommend a complete surface preparation system including: a floor grinding and polishing machine(s), concrete dust extractor(s), equipped with Hepa filter(s), diamond tooling, chemicals (densifier, sealer, dyes – optional). It is also important to receive proper training to ensure that your projects are completed in a professional, timely and cost effective manner.

Superabrasive’s LAVINA distributors offer floor grinding and polishing training classes at various locations many times throughout the year. See SCHEDULED TRAININGS / DEMOS or contact Superabrasive for details at (800) 987-8403. Typically, LAVINA trainings are two day, hands on classes, and cover topics such as: concrete floor prep, polishing process steps, chemical applications, diamond tooling options, burnishing, etc.

Choosing the proper floor grinding and polishing machine and diamond tooling is critical for the success of the job, and the following questions should be addressed first:

• How big is your project, and how much time do you have to complete it? This will determine the size of the grinder and vacuum needed, as well as how much tooling will be required. For example, a LAVINA 20 (20 inch) is appropriate for small residential projects, like garages or patios, whereas larger commercial projects will require a larger, more powerful machine such as LAVINA 30 or 32.
• How old is the concrete? Freshly poured concrete floors require at least 28 days to cure. Conversely, older concrete should be inspected for pits and cracks, which may be treated by a product such as Quick Mender®.
• What condition is the concrete in? The condition of the concrete will determine the initial grinding steps needed to prepare the floor for polishing which include coatings or epoxy removal, etc. If the floor is in optimal shape, you could start with 120 grit metals, but if the floor is uneven and blemished, you should begin with a coarser grit, such as 30.
• How much aggregate would you like to expose? If you want to show aggregate, you must grind the concrete more aggressively (longer and deeper) than if you simply want to polish only the cream.
• How hard is the concrete? Typically concrete under 2500 psi is considered soft, between 2500-4000 psi – medium, 4000-5500 psi – hard, and above 5500 psi – extra hard. We recommend testing the concrete hardness of the floor prior to selecting diamond tools. A popular and easy to use tools for testing the concrete hardness is the Moh’s pick set (scratch tester).
• How much shine do you want? If just a honed finish with less shine is desired, you may stop processing the floor after grit 400. However, a shiny and mirror-like finish will require processing the floor to a much higher grit – typically 3500. For maximum shine, you can go up to 8500 grit resin, such as Superabrasive’s V-Harr BUFF pad.
• Grinding wet or dry? This will sometimes depend on the job and job site. Most operators prefer the dry process, as it requires less clean up; however, wet grinding is best for some applications. Keep in mind that dry grinding will always require a vacuum for dust removal.
• Is your project indoors or outdoors? This will determine which sealer and dyes are needed. Some guards and sealers are appropriate for indoor applications only. Water- and acetone-based dyes are also for interiors only because they are not UV stable. Others such as ColorJuice™, however, is UV stable and ideal for concrete porches, patios, driveways, sidewalks and pool decks. Contact us for additional information about your specific job and the appropriate chemicals to use.

Understanding how diamond tools work is a must to anyone who wants to be successful in this industry. Diamonds are not all the same. The two terms most often used when speaking of diamond tools are diamond grit and bond. Most diamond tools are made of synthetic diamond powder, measured in microns and called grit, and a bonding material, usually metal or resin, or a combination of bonding materials (hybrid tools). They are bonded together through injection molding, hot and cold pressing, electroplating, and vacuum brazing.

The two most common problems that you can run into are:

1. The tools cut aggressively but their life is too short (premature wear) – this usually happens when using soft bond that easily opens on soft / abrasive floors;
2. The tools don’t cut well and just slide on the floor surface, which is called tool glazing – this happens when using hard bond tools on hard concrete. Often, adding water helps avoid glazing as well as removing weights, and slowing down a bit. However, sometimes you should just switch to a softer bond. It is best to test the concrete hardness first, and make sure you are using the correct bond tools.

Each grit is designed to refine the scratch pattern, and the rule of thumb is each consecutive grit is to be approximately doubled in size, so it can remove the scratches of the previous step. For example, if you start with 30 grit, the next grit is 50 or 70, then 100 or 120, 200 or 220, 400, 800, etc. Following proper grit sequence is a fundamental principle in concrete processing. Skipping a grit step will put you up against some serious scratched floor challenges. The grits steps are usually divided into three stages — grinding, honing and polishing.

Concrete Grinding – Popular Diamond Tooling for Grinding

Grinding includes the steps from the lowest starting grit (it depends on the floor and application and could be as low as six grit but typically 30 or 50 grit) up to 120 grit. The tools used here are usually metal-bond tools, brazed tools for lippage removal and floor leveling, or pcd tools for coating and glue removal. There are many shapes and designs on the market — round button segments, rectangular segments, single, double or multiple, plugs, etc. But what is more important, especially in the initial cutting steps, is the bond or hardness of the tools. Many contractors have trouble understanding how bonds work relative to different kinds of concrete. Depending on the bonding material, abrasives have different hardness which determines how diamonds are exposed. Hard concrete requires a softer bond to prevent glazing and to allow new diamonds to get easily exposed for maximum cutting. Soft concrete requires a harder bond, so it can last longer (soft bond will cut but it will wear out too fast on soft concrete).

Concrete Honing – Popular Diamond Tooling for Honing

Honing includes the steps between 100 to 400 grit, the tools used in this stage are usually hybrids and/or resins. The hybrids, made of a combination of bonding materials — metals, resins, or ceramics (such as Superabrasive’s Calibra discs or HD discs), are especially useful for removing scratches left by the metal bond tools.

Concrete Polishing – Popular Diamond Tooling for Polishing

Polishing is from 800 grit up to 3,500 grit. The most popular choice for concrete polishing are resin pads/pucks, which are made of poly-phenolic and ester-phenolic. Another thing to consider when choosing tools is there are bonds/tools designed for wet use only, dry use only or wet/dry use. Improper use can cause problems like glazing, sticky residue on the floor, and so on.

“Following all the grits may seem like a lot of steps, but well-trained contractors know that this is crucial for proper floor refinement and achieving a good wear-resistant floor finish,” says Elliott. “It is tempting to buy the cheapest diamonds but concrete grinding and polishing is a very labor-intensive business and lost productivity and time spent redoing a floor is much more costly.”

The point made is that not all diamond tools are created equal, and diamond tools should be always chosen relative to a specific project. Knowing what kind of concrete you are dealing with is important for finding the right combination of bonds and grits which will increase your productivity and ROI, and produce the best floor finish.

Maintenance – Popular Diamond Tooling for Maintenance

With proper maintenance, facility managers can keep their polished floors looking good at a comparatively lower cost than alternative flooring options. Traditional daily maintenance includes mopping and auto scrubbing, using only water or non-reactive cleaning agents when necessary, and cleaning spills and stains promptly. However, in order to maintain their shine and light reflectivity, polished floors require more than that. They require a maintenance program which includes periodic mechanical maintenance with diamond impregnated pads and periodic treatments with chemical cleaners. Furthermore, the maintenance program or schedule has to be designed for a specific floor (not for concrete floors in general), and it will be different from one facility to another, depending on the type of facility, foot traffic, etc. Without proper maintenance schedule in place, the floor shine quickly deteriorates and facility managers end up with a “failed” polished concrete floor.

Diamond impregnated pads are usually the tool of choice for mechanical maintenance of polished concrete floors. How often to do periodic maintenance is largely determined by the facility foot traffic. Superabrasive has developed a new maintenance program for polished concrete that equips youwith the right tools for the right job –  ONE FLOOR Maintenance program.

There are many variables a contractor needs to consider — labor, abrasives, the floor itself, just to name a few …

• Planning for repairs can be one of the most challenging issues a contractor will face when bidding an existing floor project…One thing to remember is sometimes toppings like carpeting and tile were put on a floor because the concrete was bad in the first place. Contractors usually specify spalls per square foot and cover them in the bid. Spall repairs required beyond the allowance in the bid are priced out in an addendum to the bid, as are necessary crack repairs and spalling along joints.
• If working with electrical equipment, you need to make sure power in the correct voltage will be available to you on site. If it is not, the power for your equipment will need to come from portable generators.
• Construction schedule. Find out how much time you have to perform your work and during what times of the day you can do it. If you are working under a tight schedule, or working a job on an existing building still being used for business, you may find yourself confined to do your work nights and weekends. If that is the case, you will need to pay your employees a premium and consider those extra labor costs in your bid.
• Job schedule. A job schedule, i.e., a plan that lays out when certain trades will be in a building and who they will be working around, is typically not accurate at bid time, so be prepared to be flexible when it comes time for your crew to get on site. What is especially important to pay attention to in that job schedule, however , is mainly two things: floor protection and walls. You may have to arrange for floor protection before and/or after your polishing job. Be sure it is clear in the bid who is responsible for installing floor protection and who will pay for it. You will also need to know if you will be polishing before or after the walls are built. If you get the floor before walls are up, you will have minimal edge work. But if walls are in you will have to consider the extra edge work in your bid.
• Edges and handwork.This is where all the hard work is. Edges could double your price if you have a lot of small rooms on a project.
• Samples and mock-ups take time and resources, and you may want to charge for them. If you get the job, the price the client paid for a mock-up can be deducted out of the contract.
• There are several factors that will affect your abrasives costs, including hardness of concrete and the number of steps you are required to perform throughout the grinding and polishing process.
• Cream, salt and pepper, or aggregate – if the desired cut of the floor is not clear in the specifications, make sure it is before you submit your final numbers on the job. You will see your profit disappear if you bid for a cream cut and have to spend on abrasives to handle an aggregate cut.
• Most specifications will require the polisher to do joint work on the floor. While a saw cut control joint might be 1/8-inch wide, a construction joint can be ½ inch wide. Your joint filler material needs will vary depending on the types of joints in your floor. That material isn’t free; plan for that amount in your bid. If you find out on the job you are running short, you might have to pay high costs for shipping in extra to the jobsite – costs that will come out of your pocket.
• Mix design.Find out the mix design of the concrete. It will tell you the psi of the concrete, which is one factor in determining your diamond usage for a project.
• Take a look at you job and decide if it will be a wet grind or dry grind. You will need to factor into your bid equipment and costs for dust control or slurry disposal.”

Useful information from the American Society of Concrete Contractors (ASCC) and the Concrete Polishig Council.

Part of the CPC’s mission is to establish a clear, concise, and technical foundation for the concrete polishing industry. The CPC has worked closely with polishing contractors, manufacturers, architects, and general contractors to compile the specifications, guidelines, and position statements listed here – https://www.ascconline.org/concrete-polishing-council/technical-documents.