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polished concrete

Education, Resources, and How-to

Scroll through the menu items below for educational resources and answers to frequently asked questions we receive from LAVINA users. Much of this information is provided by third party industry publications, in which Superabrasive is not affiliated, and is intended to be unbiased and educational in nature.

For more info and other common topics on how to grind and polish concrete floors, visit our FAQ page.

Choosing the right diamond tools for a floor grinding and/or polishing project.

With the increasing popularity of polished concrete, it comes as no surprise that the number of tooling manufacturers and the tooling options have grown tremendously. Understanding how diamond tools work is a must to anyone who wants to be successful in this industry.

“We have seen many people jump in the concrete polishing business thinking it is all about running a machine and swapping diamonds, and that diamonds are all the same,” says Mark Elliott, Concrete Products Manager at Superabrasive Inc. (a manufacturer of diamond tools and equipment, including the LAVINA line). “But there is nothing further from the truth. As a diamond tool manufacturer with over 25 years of experience, we know how many variables are in the manufacturing process, and they all impact the performance of each tool. It is very easy to copy the shape and design of a tool, but almost impossible to replicate the exact bond matrix and formula.”

Diamond Grit and Bond

Diamonds are not all the same. The two terms most often used are 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.

Grinding - see our diamonds for concrete 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).

Honing and Polishing - see our diamonds for concrete honing and polishing

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.

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.

Article can be found also at http://www.forconstructionpros.com/article/12043337/not-all-diamond-abrasives-are-created-equal. For more information call Superabrasive at 1-800-987-8403.

Maintenance - see our diamonds for floor maintenance

Implementing a consistent maintenance program for sustainable polished concrete floors

Over the years we have seen the interest in polished concrete explode due to its practical advantages, such as durability, cost effectiveness, easy cleaning and maintenance, great light reflectivity and stain-resistance, among others, as well as its decorative appeal. Not maintenance-free, as it has been sold sometimes.

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.

The elements of a maintenance program are typically who would do it (in house crew or outside contractors), what pads to use, what chemicals, and how often. Diamond impregnated pads are usually the tool of choice for mechanical maintenance of polished concrete floors. They are usually made of synthetic or natural hair fibers and sprayed with diamond powders and epoxy binders. These pads are available in a variety of shapes and sizes to fit all models of floor buffers, burnishers and auto scrubbers. Opt out for a pad that can be used wet or dry, and does not require waxes or chemicals, such as the ShinePro line by Superabrasive.

Some facilities prefer to do “in-house” daily maintenance and just bring an outside contractor to re-polish the floor when needed (often times not until the floor shine has worn out ). If you choose this practice, make sure your employees are properly trained what pads and chemicals they should use. The worst thing that can happen to your brand new shiny floor is to put the wrong pad or chemical and ruin the polish. In some cases, the contractor who polished the floor in the first place would provide a specialized maintenance plan along with the proper tools and chemicals, which would guarantee the quality of the floor finish.

Other facilities would hire a professional maintenance contractor to take care of the floors on a daily basis, but again, it is critical that the maintenance provider understands polished concrete and is properly trained. Unfortunately, this is easier said than done due to the high turnover in the janitorial industry.

How often to do periodic maintenance is largely determined by the facility foot traffic. Obviously, a floor that has a 1000 people per day would wear out faster than a floor with 100 people a day. Another thing for facility managers to keep in mind is that even with the perfect maintenance program in place, the look of the floor will inevitably change with time and repeated repolishing. This is because every time a part of the top surface layer is removed, more aggregates are exposed. This is especially true in high traffic areas where more aggressive approaches are needed to get through worn portions of the floor.

In conclusion there is no exact formula how to properly maintain polished floors but the key factors are training and tracking, and making adjustments to the maintenance program when necessary.

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Bidding Concrete Polishing Jobs

BY REBECCA WASIELESKI, For ConstructionPros.com, Editor

A polished concrete floor project can be a tough job to bid because of the many variables a contractor needs to consider — labor, abrasives, the floor itself, just to name a few. Derek Mackenzie, president of Floorlab in Toronto, Ontario, says a lot of this difficulty stems from the nature of concrete polishing. "The reality of polished concrete is we are the only flooring tradespeople who manufacture a floor on site working with the conditions of the job and existing materials, meaning the concrete floor," Mackenzie says. "Everyone else has quality control materials produced in a factory, like wood and tile." This reality, he says, means polishing contractors need to be prepared for anything and be ready to adjust for variables on the jobsite. It also makes defining a job's cost upfront an even greater challenge.

Harry Gressette with Polished Solution, Inc., Sarasota, Fla., emphasizes the importance of qualifying a bid, in other words, describing how you will handle all the unknowns and what ifs you might uncover on the job. Qualifying a bid helps you offer a reasonably accurate bid price upfront, but also provides protection against the unexpected and the out of the ordinary.

A strong history of job costing gives Gressette a good idea of his costs based on a number of variables, including size of the job, new or old construction, type of building (school, retail, hospital, etc.), requirement for 6- or 7-step refinement process, and so on. These variables tell him how many crew members he will need, how many pieces of equipment he will need on site and how much travel will cost. Other variables like lineal feet of edges and diamond requirements based on the mix design might take a little more digging but can usually be accurately determined at bid time. Other variables, however, like guessing a price for spall repairs on concrete you haven't seen, is the kind of variable that would require a bid qualifier.

This list of tips will help you better determine costs before you turn in your bid to a general contractor or home owner.

Repairs. Planning for repairs can be one of the most challenging issues a contractor will face when bidding an existing floor project. "With repairs, there are a lot of unforeseen issues that can arise. A lot of times you go to a project and you can't see the floor because of an epoxy coating or glues and mastics that remain after carpet or tile comes up. So you have to give a price without seeing the floor," Mackenzie says. "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.">

Gressette says this is where qualifying a bid is important. "Spall repair can eat your lunch," he says. "I usually allow so many 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.

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. "I have it in my contract that all power will be paid by the customer," Mackenzie says. The same goes for water.

Read the full story here - http://www.forconstructionpros.com/article/10631892/12-tips-for-bidding-concrete-polishing-jobs

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Why polished concrete is “Green”

by Sherry A. Boyd

Just a few short years ago, saying that concrete was a green building material was sufficient. It was taken for granted that concrete, being locally produced, durable and nontoxic, was a sound, sustainable choice. Today, it is not enough to repeat the word “green” like a mantra. Whether they are green-skeptics or advocates, consumers and architects are becoming better educated and more concerned about environmental impact, and they want substance.

The next step is to improve our green accountability as an industry, even beyond talking about LEED points. As an industry we have to increase transparency by providing more details and disclosure. It may sound like extra work, but when we use the facts we can win on the issue of “eco-value.”

Documenting any green claims is vital. There is no doubt that litigation and government regulation of green criteria affecting our industry are looming issues. The Construction Specifications Institute has been offering courses to advise specification writers and their employers about the risks of promising sustainability and energy efficiency, but not delivering it.

Generalizations must be replaced by specifics. For instance, “recycled content” is a very broad umbrella term open to misinterpretation and the design and building community won’t accept lack of further information. Savvy buyers are asking to know the exact percentage of any materials we use, broken out as preconsumer, post-consumer or post-industrial. Are manufacturers you choose delivering a consistent product and providing this information?

Even though not all customers will require it, you can demonstrate green thinking when you make it standard practice to point out the exact low-VOC content of surface-applied liquids, such as sealers, curing compounds and other treatments, used on a job. Products are available that meet and exceed local requirements, and it is easy to find specifics in MSDS documents to show your customers that you are committed to being an environmentally conscious company.

When you are ordering ready-mixed concrete for new construction, have you been asked to have your supplier document and certify the amount and type of recycled content and local materials used? Often architects ask for this for LEED projects. Examples of recommended documents are supplied in the appendix of the Ready Mixed Concrete Industry LEED Reference Guide, prepared by the RMC Research & Education Foundation. This report provides a good benchmark of standard procedures in the ready-mix concrete industry.

Do you document the procedures that you use to manage construction waste? That is required on jobs that either will be submitted for LEED certification or are said to adhere to LEED criteria. Shouldn’t that be done even when you aren’t involved in LEED projects? It shows your company uses environmentally sound procedures for reuse and recycling, giving you an excellent selling point. It might even make the difference in a competitive bid, allowing you to demonstrate you are greener than the competition.

If you want to increase green demand for all types of decorative concrete, it’s important to quantify its eco-value to the building owner or building operator, whether you are doing a big commercial project or a smaller personal residence.

As a good example of how to promote green benefits, examine the reasons why polished concrete has become a phenomenal top seller in these challenging financial times. Manufacturers and installers used the hard facts and cost comparisons as market drivers. First, the lower installed cost of polished concrete compared to alternative materials is a selling point. Second, the higher potential replacement cost of other materials over the floor’s life span can be spelled out in dollars and cents. Third, there are the benefits for building owners and operators of eliminating toxic cleaning materials and reducing maintenance time and expenses. These three key benefits create eco-value.

Architects designing buildings that would apply for LEED certification have influenced the increasing demand for polished concrete, but more and more non-LEED projects employ polished concrete, too. The strong message trickled down, and demand increased for polished concrete in homes, schools and office buildings that won’t ever spend the money to apply under LEED. We see an increasing number of projects that just have a goal to be considered environmentally responsible.

A strategy focusing on eco-value and key market drivers can increase demand for other decorative concrete methods, too. To be more direct, you can stop selling against each other and start selling against the costs and benefits of other types of material alternatives that are less durable, more expensive to maintain, wear out more frequently and have to be replaced. When you think about it, bamboo floors don’t perform so well when compared to concrete or cementitious toppings. In the present economic situation, almost any materials in the decorative concrete field can win on long-term value comparisons. Instead of seeing LEED criteria as an end point, why not look at these criteria as a starting point for developing a sales strategy applicable to the wider market? Yes, the U.S. Green Building Council LEED program has set new standards that decorative concrete contractors must understand. But don’t dismiss the follow-on effect on the whole building industry.

Anyone in your firm who has contact with your customers would benefit from more education on the vocabulary of sustainability and green building. Consumers are reading up on the topic and have probing questions. Designers, builders and architects are experts in the vocabulary promoted by the USGBC and other groups. Vague answers to their questions will only make us look like we are engaged in “greenwashing.” We offer a truly sustainable solution. Can you get specific? Are you keeping up?

Ultimately, I believe that the concrete industry and the dimension that decorative concrete offers will play a major role in determining the success of green building initiatives and sustainability efforts. So many low-energy building designs use high-thermal-mass concrete floors and walls in structural design. We have to reach beyond the focus on LEED points to address the larger need for improving, repairing, renovating and maintaining this vast amount of concrete in the built environment. In green building criteria, when life-cycle cost is seen as important, concrete will outperform alternatives. The larger topic of eco-value is the next hot topic beyond green, and decorative concrete can prove its worth.

To read the full article, visit http://www.concretedecor.net/decorativeconcretearticles/vol-11-no-6-august-september-2011/green-matters-be-prepared-for-tough-questions-about-e2809cgreene2809d-concrete/.

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How much should I charge per square foot?

Some useful articles about cost estimating and bidding for concrete polishing jobs:

12 Tips for Bidding Concrete Polishing Jobs - ForConstructionPros.com

Fundamentals of Business: Setting the Right Price for Your Services - Concrete Decor

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How can I determine a floor's flatness?

Here are some good articles talking about concrete flatness from the leading industry publications:

Using F-Numbers for Measuring a Concrete Floor's Flatness - Concrete Decor

Evaluating Flatness and Levelness when Polishing Concrete - Concrete Construction