Concrete floor grinding is very popular in the construction industry; it is the process of smoothing the concrete and also making them glossier by using a series of diamond tools and sealers. There are big benefits of grinding the concrete floors, it can make the concrete floors with good looking, and also make cost-effective maintenance on concrete floors.
Except for the concrete grinding, there are other flooring options, like the vinyl layer on unpolished concrete floors. However, the unpolished vinyl flooring are easily gotten damaged or worn along with the rate of use, or the changes of wear conditions. While the polished floors are very durable and have high wear resistance. Due to the durable nature, there is only minimal maintenance is needed. It may take up to 10 years before doing the restoring the concrete floors.
Just by grinding and polishing, the concrete floor will get good looking, no need the purchase and installation additional materials. Also, the polished concrete floor only requires minimal maintenance. So it is really cost-effective to do concrete floor grinding.
Always keep in mind that “safety is the priority”. Do remember to wear the PPE (Personal protective equipment), including the dust mask, ear protection, goggle, foot and hand protection devices.
If there are damages and cracks on the floor, then a repair kits is needed. a crack chaser blade and joint sealing material are necessary.
Grinders are varies in different sizes, weight, power and direction of rotation, etc. according to the size of your floor as well as the concrete conditions to choose the most suitable grinder for your needs.
Diamond tools determine the efficiency of the grinding process; you need to choose the diamond tooling with right grit and metal bond hardness. Generally the 14 grit, 30 grit, 70 grit and 120 grit are the frequently used grit sizes on metal bond diamond tooling throughout the grinding process. When come to the bond types, it depends on the concrete hardness, if the floor is hard, the metal bond should be softer, in opposite the metal bond should be harder. After choosing the diamond tooling ,it is necessary to check diamond tooling after a pass or two to determine if the concrete is too soft causing excessive wear or if the concrete is too hard and it’s not grinding much at all
For starters, it is easier to achieve better polishing results with harder floors. Liquid hardeners are used to make concrete floors harder and denser. Hardening also helps to protect the floor from water penetration, staining and future damages.
If the concrete is extremely hard and there are heavy sealers on it, then the 14 grit tooling or PCD tooling is needed. However, before using the 14 grit, pls do to evaluate the concrete condition again, make sure to use the14 grit diamonds as the first step if it is absolutely necessary. Because it will take a lot of time to get the heavy scratches out left by the 14 grit diamonds or PCD tooling.
Do remember using concrete vacuum to clean the entire floor (mopping and wet vac pickup is an option for smaller floors). The key is to clean up all dust and diamond grit that drop from the diamond tooling. If you don’t clean up after each step, the subsequent grits will grind over top of residual bigger diamond grit, which will create scratches on the floor.
30 grit diamond tooling is the most used grit size; all of the primary grinding steps will be finished with 30# grit tooling. If you want to expose the aggregate, it must be completed by the end of this step. By running the grinder at a lower RPM, the grinding speed can be increased, then the diamonds will penetrate the floor without getting overheat.
If there is any patch or repair work is needed, then the repair work should be done after 30 grit grinding. Also, another 30 grit grinding is required after the repair work is completed.
Fix medium bond 30/40# metal bond tool to handheld grinder or walk behind grinder, Start at one side and grind from“west to east” across the entire concrete floor. Make sure to overlap the grinding pass as close as possible to the previous grinding pass.
After the grinding process is finished, clean up the floor with vacuum or scrubber.
Change the direction and go “north to south” pass after the “west to east”, still take care of the overlapping, make sure the grinding passes overlap one another as close as possible. Do the same cleaning job again.
It is better to use grind the floor in swing style, in this way, the grinding passes can be blended. Also, take care of your pace during grinding, it is great if the grinder leaves solid grinding pass. However, if there is swirl grinding passes on the floor that means you push the grinder too fast, you need to slow down. Also, there may be the occasion that the grinding speed becomes slow suddenly, it is possible that the soft top layer has been remove off, the harder concrete comes out, so you need to replace the medium hard tooling with a more softer bond.
After the “north to south” pass completed, have a short break, check the entire floor carefully. If the exposed aggregate doesn’t meet your expectation, then go back and repeat the grinding process until get the exposed aggregate as you want.
Replace the medium hard 30/40# tool with Medium hard 60/70#, grind the perimeter of the floor as you did in step 2. After the grinding is done, do the clean job again.
Still use the 60/70# tooling, repeat the grinding process.
The initial scratches left by the 30/40# should be removed in this step, if you still can see the significant scratches, do the grinding until all the big scratches are gone.
Remember to vacuum the entire floor area before moving to next step.
Change to the 120/140# diamond tooling and repeat the grinding process. Vacuum the entire floor area carefully and check your grinding job so far. Do extra grinding job if needed.
Use the 50 grit or 100 grit resin polishing pucks to do transition grinding, to make preparations for the polishing job in the following steps.