All seasoned epoxy applicators will agree that thorough surface preparation is key for the long term success of a successful flooring project. There is nothing more heart breaking for a client to discover his beautiful epoxy floor to start chipping and breaking just a few weeks or months after completing. Most of the time poor surface preparation is the culprit. The substrate had not been properly ground, cleaned and prepared to be able to accept the epoxy.
So what constitutes proper surface preparation? Which method is the best? This is a good question as depending on the application in question you may need to approach the problem in a different manner. I have identified several levels of surface preparation according to their mechanical intensity. Some methods (like sanding) are light and barely scratch the surface. Other methods (like scarifying can) be deep and intense.
Sanding Your Epoxy floor Coating
This is the lightest form of surface prep usually done with an angle grinder or a light floor sander. Done with sanding paper (of varying grits) attached to a disc. Such surface prep is only appropriate for re-coat jobs, or if you are just applying a light paint job. Even if you use a rough, low grit sandpaper, the surface scratch will be little
Many homeowners are opting for exposed concrete floors in their homes, because they can be attractive and are easy to keep clean. Before you can add a colored stain followed by a coating of epoxy, urethane or wax to make a concrete floor shine, you must prepare the floor’s surface. A professional floor buffer or sander equipped with a sanding disc can remove any existing paint, stains, discoloration or small imperfections from the floor’s surface.
Stone Grinding
These machines were very popular before diamond grinders came out, but I see that epoxy applicators are not using them much these days. Basically this is a heavy floor grinder that has stone tools fastened to the bottom. Works well for a soft concrete surface but it does not grind well on hard concrete or epoxy.
Learning how to grind a garage floor for an epoxy coating or paint hasn’t always been the easiest or most straight forward of projects for the average home owner. It frequently raises more questions than answers and can lead to frustration when trying to figure out the best way to do it. Many of these questions relate to what type of grinding equipment to use.
This process of grinding your garage floor is much easier to manage than the traditional 7″ angle grinder with a concrete turbo cup wheel. Plus, it keeps you off your knees. The large size of the tool covers more area and the flexible blades prevent grooving or kiss marks that can happen when a turbo cup wheel is not held flat and goes up on edge.
today, we are going to be going over 5 things you need to tackle before tackling garage floor coatings .When it comes to looking for a epoxy garage floor coating, this is a process that needs to be done with patience to make sure you know exactly what you need. The garage is a complex setting that ranges in use from home to home so not every garage will require the same coating so not everyone’s recommendation will mean the same thing for your need. Down below, we have outlined what you need to think about before getting started on your garage floor coating, so let’s get started!
Diamond Grinders Your Concrete
I love diamond grinders because they are so versatile. Most diamond grinders allow easy switching out of diamonds. They can there fore handle all types of floors from soft cement to hard concrete. They can strip old paint layers and clean out oily patches of the floor. Diamond grinding leaves a much deeper and harsher scratch profile of the floor (compared to sanding) and this therefore enables better bonding of the primer to the floor. I also find if you are dealing with messy and contaminated patches, a bit of persistent diamond grinding is enough to give you a nice clean floor. This is my preferred choice if I’m working with standard floor systems up to 2-3mm. Watch this video to understand how a diamond grinder works
Shot-blasting your epoxy floors
is a more aggressive method of surface preparation than grinding. It leaves a nice deep profile that makes the bonding conditions for high build flooring systems (3mm and over) ideal. However shot blasting requires very good high quality concrete to work properly. If you try shot-blasting a weak substrate you could very well end up damaging the substrate.
Finally, Scarifying is my solution of last resort. This is a very aggressive form of surface preparation that digs into the surface. Several time when I was faced with horrible looking contaminated floors, using a scarifier saved the day. We were able to clean the surface and apply a new thick heavy build coat.
Final cleaning your epoxy floors
Once the grinding is done, it’s time to make sure the garage floor is clean of all the dust. If you ground the floor wet, then chances are the floor is clean.
To check, run your fingers across the surface when it has dried. If your fingers don’t have a lot of white residue on them, then you are good to go. Another test is to press a strip of duct tape to the concrete and then pull it up. It should stick fairly well and come up clean without too much dust. The floor will never be completely free of concrete dust, so don’t fret over small amounts on your fingers.
If you have a lot of white residue after a wet grind, then this is excess concrete dust that did not get hosed out well and will need to be cleaned. The best way is to mix up a solution of TSP (Trisodium phosphate) in a bucket, spread it out on the floor and lightly scrub it with a push broom or long handled scrub brush.
Using your high pressure nozzle, rinse the concrete real well making sure there is no more solution left behind. Work in sections if you need to so that the solution will not dry before you rinse it out. This will help lift any remaining slurry and dust that is in the pores of the concrete when you rinse.
If you did a dry grind, the easiest way to insure the concrete is clean and ready is to use the wide mouth attachment on your shop vacuum and just vacuum all the dust up. What’s nice about this method is the fact you can start right away with applying your floor coating since there is no water on the floor that needs to fully dry.
Once the floor is done, test different areas by sprinkling water drops on the surface, paying particular attention to any areas that were coated in oil or grease or where you may have used a tire dressing that dripped onto your concrete. It should turn the concrete darker and absorb the water fairly quickly. If it just sits on the surface, then you may need to regrind and/or re-clean that spot before you apply your coating.
Grinding a garage floor with one of these easy methods will ensure the best profile for your garage floor coating to adhere to. It can be done in less than a day and is safer than using an acid etch.
As a final comment, the thicker the system that you plan to apply the deeper the preparation needs to be. This holds also vice versa. If you scarify a surface, you need a thick coating to cover that surface. A thin epoxy coat will not be able to fully cover the heavily scarred profile.
What are your thoughts on surface preparation? Please leave your comments below! And if you got value from this article, then maybe you should consider our online course for epoxy flooring! You will get many more useful insights and information in this jam-packed course.
