Concrete floor painting is often left to the professionals due to the intensive prep requirements that are required in order to do the project to the best standards. There are some DIY products that do an admirable job, but fall short if you are going for a long lasting coating that won’t easily scratch or peel off the concrete in time. I will leave the DIY methods up to the product manufacturers since they all make extensive videos and PDF instructions for their unique products.
Preparing the Concrete
Some amount of time and expense will need to be spent on the preparation step. Our team begins with the removal of any previous coatings including any sealer. Concrete sealer will act as a bond breaker and any newly applied coating will simply not fully adhere. If your coating is a paint or floor coating, you will need to begin with carbide blades on a concrete floor prep machine. You can rent these from a rental company for around $175 per day and the blades will set you back around $350 for a set. You will also need 220v electrical service or a good sized generator to power the equipment. With this setup, you should be able to remove all the coatings on a 20×30 area in around four hours or so. Thicker mil coatings will take longer and, sometimes, even more aggressive methods to remove.
If your floor is just sealed or you have completed the coating removal step, you will now be able to do the grinding step to open up the pores in the concrete to receive the new coating. Our team starts with a 60 to 80 grit diamond grinding set. These will set you back another $400 or so, but you should not skip this step! You new coating will likely fail if you skip it. This step goes a little faster then the previous step and is the last step if you have fairly dense concrete. For soft concrete you will need to run a 200 to 300 grit set over this one to remove any scratching. A 20×30 area will take about two to three hours to complete for each pass.
Our team always follows the grinding step up with a good vacuuming to extract all the dust form the pores in the cement to ensure your coating will bond properly. After this, you should be ready to paint the floor.
First Coats
Before we begin, we always like to run a damp cloth across the floor to make sure all of the dust is removed. If the cloth is dirty, keep cleaning until it is clean! Make sure you read the coating PDS or TDS before you begin. Many floor coatings require a diluted first coat to ensure penetration and bonding. We usually recommend a three coat system for floors. A diluted first coat or primer as required by the TDS, a thorough first coat, and a final coat of floor paint or a clear coat. Just ensure you follow all the directions before you begin.
Some coatings are very susceptible to moisture issues. If you are using one of these coatings, you will need to perform a moisture test. This is usually easily accomplished with a calcium chloride test. You can obtain these online for less than $20 each. Most contractors will do tests in several areas to ensure you don’t have ‘wet’ spots under the slab. If the test results are good, you can apply the first or prime coats.
Top Coats
The product data sheet (PDS) or technical data sheet (TDS) will tell you the time frame to recoat. With most flooring products they will recommend an 8 to 24 hour wait time. I recommend following these directions as floor coatings can be very finicky when it comes to topcoating. When you are all finished up, pay special attention to the wait time until you can return the floor back to service. Most coatings want you to wait at least 48 to 72 hours for heavy traffic. Once that recommended time goes by, you can enjoy your new floor!
Concrete floor painting isn’t a very DIY friendly project and might not be for everyone – especially if you don’t like projects that take days to finish because of the wait times. Our team are experts at these projects and we can even lend you a few box trailers for the contents of your garage or area while the project is underway. Just give our project consultant team a call if you’d like to explore more about concrete floor painting.
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