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Frequently Asked Questions

What are the benefits to polished concrete?
  • There are many advantages: it is a durable type of floor, as well as being cost-effective and easy to maintain, dust proof, LEED-friendly, stain- and slip-resistant, and it has increased reflectivity reducing the amount of electric lighting required.
  • The life expectancy of a concrete floor will surpass most other flooring surfaces making it a common choice for retail stores, warehouses, manufacturing facilities, restaurants, schools, hospitals and office buildings. Polished concrete floors are also becoming more and more popular in residential homes.
  • It is durable and can easily handle heavy machinery, forklift activity, and extensive foot traffic.
  • Polished concrete is easy to clean and maintain with no chemicals or waxes required, eliminating the labor, time, and expense to apply them.
  • Polished concrete floors have as much traction as other untreated concrete surfaces and are about 40% less slippery than a hardwood floor, waxed linoleum or polished marble.
  • The high light reflectivity of polished concrete is another benefit, especially for office buildings, hotels, restaurants, and other public facilities that want to project a bright, clean, professional image.
  • Polished concrete may be stained or stenciled to add character and further improve its appearance. The available options for coloring concrete and other decorative options is endless.
  • Polished concrete is a popular flooring solution because of its practical advantages, as well as its decorative value.
What do I need to get my concrete polishing business started?

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

Because All Star Rents has all of the machines available for rent, you can start your business at a much lower cost. Plus, our Territory Manager can assist and guide you through the process to help you become profitable more quickly.

Where can I get trained and certified on the LAVINA system?

All Star Rents holds regular Concrete Polishing Certification classes throughout the year. Additionally, we have color, sealer and overlay product manufacturers doing demos. Check out our Training Calendar for dates and cost.

Which floor grinder and diamonds should I select?

Choosing the proper floor grinding and polishing machine and diamond tooling is critical and dependent on the scale of the project. The following questions should be addressed first:

  • How big is your project, and how quickly must it get completed? This will determine the size of the grinder and vacuum needed, as well as how much tooling will be required. For example, a 20” machine is appropriate for many residential projects, like garages or patios, whereas larger commercial projects will require a larger and more powerful machine.
  • How old is the concrete? Freshly poured concrete floors should not be polished until after at least 28 days to cure. Conversely, older concrete can be harder and more likely to have pits and cracks, which will require extra work to patch.
  • What condition is the concrete in? The condition of the concrete slab will determine the initial grinding steps needed to prepare the floor for polishing which include coatings or epoxy removal, etc. In most cases we would recommend starting with 30 grit diamonds. However, a very flat and damage free slab may be different.
  • 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. Ultimately, the unique characteristics of the slab will dictate the available finish. This is why a demo area is recommended so you can establish the expectations of the finished product.
  • 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 have hardness testing tools to help establish this.
  • How much reflection do you want? A typical big box store like Wal-mart or Costco is typically around 400-800 grit. While a high-end retailer such as Nordstrom may want a finish akin to granite or marble which would be 3500 grit.
  • Grinding wet or dry? This will sometimes depend on the job and job site. It is really a personal preference. Some polishers like the finish of a wet grind better but they have to contend with “slurry management”. Many prefer dry to wet because of it can produce a great finish without the hassle of the slurry.
  • Is your project indoors or outdoors? Few outdoor projects should be “polished” due to the fact that outdoor projects can be exposed to rain. Any smooth surface (tile, concrete, etc) that gets wet can become a safety hazard.
Choosing the right diamond tools for a floor grinding and/or polishing project

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. Speaking of tooling bonds, there are two common problems that you can run into: the tools cut well but their life is too short (premature wear) - this usually happens when using soft bonds that easily open on soft / abrasive floors; or, the tools don't cut well at all and just slide on the floor surface, which is called tool glazing - typically happens when using hard bond tools on hard concrete.

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

Grinding is the first step and includes grits as low as six grit but typically 30 or 50 grit and up to 120 grit. The tools used here are typically metal-bond tools or pcd tools for coating and glue removal. There are many shapes and designs on the market . 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

Honing includes the steps between 100 to 400 grit, the tools used in this stage are usually cermic hybrids or resins. The hybrids, made of a combination of bonding materials — metals, resins, or ceramics, are especially useful for removing scratches left by the metal bond tools.

Concrete 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.

The “Steps”

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. It is tempting to buy the cheapest diamonds or skip grits but concrete grinding and polishing is a very labor-intensive business and lost productivity and time spent redoing a floor is more costly.

The point 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. Better to spend the time doing it right, once, then the labor to go back and repair mistakes from poor diamond choices or skipping steps.

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 with diamond impregnated pads using only water or non-reactive cleaning agents when necessary, and cleaning spills and stains promptly. They also require occasional re-application of sealer depending on the foot traffic and reflective properties desired. 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. Talk to us about a maintenance program for polished concrete that equips you with the right tools for the right job.

How to estimate your cost and bid for grinding and polishing jobs?

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

  • Repairs. 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.
  • Utilities. 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. 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. The real value to samples is setting the expectation for the customer about what the finished product will look like. This is a critical step in the bid process. If the slab they have cannot look the way they want due to aggregate in the slab or other variable…better to know before the job is complete!
  • Abrasives. 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.
  • Cut. 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.
  • Joints. 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. Plan for that material 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. 
  • Disposal. 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."