Concrete is the single most used material on earth. In the foreseeable future, there's no other man-made material that can substitute concrete to meet humans' need for housing and infrastructure. Be it foundations or floors, patios or sidewalks, the importance of concrete cannot be undermined.
Since there will always be a need for concrete, there will always be a need to keep it polished and looking its best. Property owners increasingly realize the benefits of grinding their concrete floors. Besides improving the aesthetic appeal of a property, concrete floor grinding results in a durable surface with few maintenance requirements.
If you're interested in starting your own concrete grinding and polishing business or are thinking of expanding your business into floor grinding, it's extremely necessary for you to know the ins and outs of the grinding process. This article gives helpful insights on how to grind a concrete floor more efficiently. Let's get right to it, shall we?
Equipment and Tools for Concrete Grinding
It's a no brainer that having the right equipment and tools for concrete grinding is crucial. You want the best combination of tools and equipment that will result in maximum performance and flexibility at a minimum cost. The following are the right tools for the job:
· Concrete floor grinder
A grinder is a must-have tool in the concrete grinding process. Concrete grinders have various applications and use cases, including cleaning, grinding, and polishing concrete floors. The grinders employ horizontal discs that revolve to polish off rough surfaces and smooth rough edges.
There are two types of concrete floor grinders: traditional large and bulky models used for patios and floors, and newer, compact handheld models that are generally used for worktops. While each type requires different skills, both achieve the same result.
· Vacuum dust collector
Although you can grind concrete floors using either dry or wet methods, the trend today is to go dry. Not only is the dry method faster and more convenient, but it also doesn't leave behind the messy slurry that wet grinding creates.
During the concrete grinding process, concrete floor grinders tend to create a huge amount of dust. This makes the use of dust-control equipment mandatory to keep concrete dust from going airborne. In this case, a dust vacuum collector will come in handy. When using a dust collector, less than 0.03% of the dust particles escape into the air, thus greatly reduces the risk of lung diseases.
Most concrete grinders don't come equipped with an integral dust vacuum collector, which means that you'll have to buy a separate unit. Some manufacturers sell dust extractors specifically for use with their grinders. If that's not the case, however, you'll have to shop around for one.
· Diamond cup wheels
Every concrete grinding business requires a variety of diamond cup wheels to complete most concrete grinding projects on time. Concrete varies in hardness depending on the mix that was used, and you need to have at least one diamond cup wheel for softer concrete and one for harder concrete. Other frequently used diamond tools include grinding diamonds, polishing pads, PCD diamond tools, and grinding plates.
· Situp grinder attachment kit
A situp grinder attachment kit consists of a welded steel frame and a mounting bracket that attaches to a grinder to allow you to use the grinder while seated on a mobile chair or stool. Adding this kit turns a hand grinder into a serious concrete grinder that saves your back and your knees while increasing productivity and the quality of edge grinding.
In addition to the above tools, there are also a variety of accessories that you should consider. They include the vacuum horse sweeper tool, accessory pins, and HEPA Filter cover kit, among others.
Preparatory Work for Concrete Floor Grinding
With the right equipment and tools ready, preparatory work for concrete floor grinding should commence. The following are the things that go into grinding preparation:
Measure the size of the concrete floor and decide which equipment (hand grinder, cub floor grinder, or satellite grinder) is ideal for the job.
Evaluate the condition of the concrete floor to see if there is any damage.
Measure the hardness of the concrete floor to determine which type of diamond cup wheels to use.
Always keep in mind that safety is the priority. As such, wear personal protective equipment, including eye protection, ear protection, dust mask, footwear, and gloves.
6 Steps for Concrete Floor Grinding
1. Remove existing coatings
The first step in grinding and polishing concrete is removing any existing sealers, paints, or epoxy coatings. Diamond grinding can remove most coatings.
2. Patch up cracks
Before polishing the concrete floor, you must first evaluate the condition of the surface. It would be best if you look out for low or high spots, minor cracks and blemishes, and joint spalling. For minor surface imperfections, diamond grinding can remove them easily. For major surface imperfections such as major cracking and joint spalling, however, you may need other remedial methods such as patching.
3. Start rough grinding
This is basically a three- to four-step process, depending on the condition of the concrete floor. In most cases, you'll begin with a coarse 40-grit metal bond tool. The 40-grit tool is for standard concrete grinding and is ideal for grinding concrete that is medium-hard. If you're grinding a concrete floor that is extremely hard, consider using a 14/16-grit metal bond tool.
When rough grinding, begin from one side and grind from west to east across the entire concrete floor. Be sure to overlap the grinding pass as close to the previous grinding pass as possible. After several passes over the concrete floor with the 40-grit metal bond tool, repeat the process with a finer 80-grit and 150-grit metal bond tool. Remember that each diamond grit step requires an average of two passes, depending on the concrete density.
After grinding from west to east, you should change the direction and grind from north to south. Again, ensure that the grinding passes overlap one another as close as possible. It is advisable to grind the concrete floor in swing style to ensure that the grinding passes are well blended. Also, be sure to maintain a slow pace during grinding to avoid swirl grinding passes.
4. Solidify and densify the concrete
After doing the initial rough grinding with the metal-bonded diamond abrasives, it's usually beneficial to solidify and densify the surface. This involves applying a liquid chemical hardener to the surface. In addition to producing a better polish, the process provides the surface with extra protection from staining and water penetration.
To solidify and densify the concrete, you should use a stiff-bristled broom to apply the hardener abundantly to the surface, ensuring that the surface is well saturated. Leave the hardener for about 30 minutes to ensure that it penetrates deeply into the concrete floor. Remove any excess hardener using a floor scrubber or squeegee. Allow the hardener to cure for 12-24 hours or as instructed by the hardener maker.
5. Start the final polishing
After waiting for 12-24 hours, you should proceed with this step that involves polishing the concrete surface with diamond abrasives embedded in a resin matrix. Begin by polishing with a 100-grit resin bond, then switch to finer grits until you achieve the desired sheen. If you want to achieve an extremely high-gloss finish, you should go up to a final grit of 3000.
6. Protect polished concrete
After obtaining the look that your client is striving for, you may want to protect the concrete floor by applying a commercial stain-guard product. This step is necessary, especially if the concrete floor will be exposed to chemicals, oil, or grease. Using a commercial stain-guard protector makes the concrete floor more resistant to dirt and stain absorption. You can use a wax applicator or pump sprayer to apply the stain-guard protector.
Now that you're equipped with the basic knowledge of grinding to get started, all you need is some patience and curiosity to experiment with different grinding tools. If you're looking for the right concrete grinding equipment and tools to kick-start your grinding business, be sure to check out Onfloor Technologies to get everything that you need under one roof.
Contact us today to learn more about how to grind different types of concrete floors like a pro.