Floorguy
Well-known member
I have done hundreds of floors and have seen lots of question on here about that subject. I wrote a 4 pager that covers the basics. Sorry for the long length but there is lots of stuff to consider to do the job right and once.
I am not posting this to try and get business as most of you are out of my area anyway. I post this to try and solve at least a little of the mystery, and hope someone finds it useful.
I have read numerous posts on this and other forums about epoxies that fail and see questions all the time about which product is best. I will try to give everyone some basic information that will allow you to make good decisions about your epoxy choices. I will not use brand names so as not to look like I am trying to sell product or services on this site. I have done literally hundreds of floors with 0 failures since starting my own business 4 years ago.
I can’t cover all floor types in this short (ha ha) primer. There are basically three different types of common floor processes. The first being a tinted solid color, gray, tan, red, or blue. There is also the random flake style floor where chips or flakes are broadcast into the wet epoxy for a random flake look. There is also the full coverage flake floor where all the color comes from the flake and is broadcast to rejection, then scraped before applying the topcoat(s).
Preparation
Like any other painting or coating job, preparation is the foundation to getting a job that looks good and performs well long term. The objective is to insure that there is no moisture coming from the concrete, the concrete is free of contaminates, and the surface is ready to accept a coating.
To test for moisture, tape a large garbage bag to the floor on all sides and leave it for a few days. When you pull it up, if there is moisture present then you have a problem and you need to use a primer that is designed to be used in high moisture areas. These are more expensive but a must if you want your work to look good and last. There are calcium chloride test available to test for moisture but the plastic will basically do the job. Both of these tests are a snapshot in time, so if you have the time to test during the rainy season things could look different.
If you do not see moisture one can proceed with preparation. The objective here is to rid the surface of any contaminates and get the surface to feel like medium grit sandpaper. Kitty liter is good at getting large amounts of oil to the surface. I also use brake cleaning fluid to do a final clean of an area.
There are numerous ways to prep the surface and I will touch on each briefly. Acid etching is probably the most popular for the DIYer because it is cheap and readily available. That does not mean it is the best method for prep. The objective here is to mix muratic acid 1 to 4 with water, cover the surface evenly and wait about 15 minutes for the
Bubbling to stop. Using a power washer to clean it off will help insure it’s removal and also do a little removal of loose material at the same time. Mix some baking sodaand water and sprinkle over the surface to neutralize the acid left on the floor. This is very important or there will be potential for floor failure. If you are using a package product that includes a cleaner make sure the surface is clean when completed.
Grinding is the next best method for prepping your concrete. One could do it by hand with a belt sander or orbital sander if your knees can take it, or they rent standup sanders at HD or Sunbelt. Again, the objective is to remove any contaminants and rough up the surface to medium grit sandpaper.
If cracks are found and you want to repair them a diamond blade on an angle grinder can be used to widen the crack so material can be used to fill the crack. Trying to get a thick filler into a tiny crack is next to impossible to do. Once the filler is dried grind it level with the floor and you are done. My suggestion is to fill cracks and grind just before you are ready to apply the coating as you don’t want the filler to have set for more than 6 hours as it could reject the epoxy coating.
The best method to prep a floor is shot blasting as it leaves a great profile on the concrete for accepting a coating. These can also be rented from HD or Sunbelt in larger metro areas. There are also companies that do that for a living but most will not want to work in small areas like a 2 car residential garage as their equipment is designed for much larger areas.
The shot blaster will also uncover cracks in most concrete as it will remove the “cream” from the top of the concrete. Again, widen with a grinder, fill and grind level once dry.
On most homes here Texas there is a raised area that has been covered with cement product for looks purposes. Hit it with the handle end of an old screwdriver and listen to insure that it is solid. You will hear a hollow sound if it is not adhered well. Remove any cement before coating if it is loose. Grinding a bevel on any removed are will make it look acceptable. Better to get it off now then have it break off later and leave an ugly spot.
I am not posting this to try and get business as most of you are out of my area anyway. I post this to try and solve at least a little of the mystery, and hope someone finds it useful.
I have read numerous posts on this and other forums about epoxies that fail and see questions all the time about which product is best. I will try to give everyone some basic information that will allow you to make good decisions about your epoxy choices. I will not use brand names so as not to look like I am trying to sell product or services on this site. I have done literally hundreds of floors with 0 failures since starting my own business 4 years ago.
I can’t cover all floor types in this short (ha ha) primer. There are basically three different types of common floor processes. The first being a tinted solid color, gray, tan, red, or blue. There is also the random flake style floor where chips or flakes are broadcast into the wet epoxy for a random flake look. There is also the full coverage flake floor where all the color comes from the flake and is broadcast to rejection, then scraped before applying the topcoat(s).
Preparation
Like any other painting or coating job, preparation is the foundation to getting a job that looks good and performs well long term. The objective is to insure that there is no moisture coming from the concrete, the concrete is free of contaminates, and the surface is ready to accept a coating.
To test for moisture, tape a large garbage bag to the floor on all sides and leave it for a few days. When you pull it up, if there is moisture present then you have a problem and you need to use a primer that is designed to be used in high moisture areas. These are more expensive but a must if you want your work to look good and last. There are calcium chloride test available to test for moisture but the plastic will basically do the job. Both of these tests are a snapshot in time, so if you have the time to test during the rainy season things could look different.
If you do not see moisture one can proceed with preparation. The objective here is to rid the surface of any contaminates and get the surface to feel like medium grit sandpaper. Kitty liter is good at getting large amounts of oil to the surface. I also use brake cleaning fluid to do a final clean of an area.
There are numerous ways to prep the surface and I will touch on each briefly. Acid etching is probably the most popular for the DIYer because it is cheap and readily available. That does not mean it is the best method for prep. The objective here is to mix muratic acid 1 to 4 with water, cover the surface evenly and wait about 15 minutes for the
Bubbling to stop. Using a power washer to clean it off will help insure it’s removal and also do a little removal of loose material at the same time. Mix some baking sodaand water and sprinkle over the surface to neutralize the acid left on the floor. This is very important or there will be potential for floor failure. If you are using a package product that includes a cleaner make sure the surface is clean when completed.
Grinding is the next best method for prepping your concrete. One could do it by hand with a belt sander or orbital sander if your knees can take it, or they rent standup sanders at HD or Sunbelt. Again, the objective is to remove any contaminants and rough up the surface to medium grit sandpaper.
If cracks are found and you want to repair them a diamond blade on an angle grinder can be used to widen the crack so material can be used to fill the crack. Trying to get a thick filler into a tiny crack is next to impossible to do. Once the filler is dried grind it level with the floor and you are done. My suggestion is to fill cracks and grind just before you are ready to apply the coating as you don’t want the filler to have set for more than 6 hours as it could reject the epoxy coating.
The best method to prep a floor is shot blasting as it leaves a great profile on the concrete for accepting a coating. These can also be rented from HD or Sunbelt in larger metro areas. There are also companies that do that for a living but most will not want to work in small areas like a 2 car residential garage as their equipment is designed for much larger areas.
The shot blaster will also uncover cracks in most concrete as it will remove the “cream” from the top of the concrete. Again, widen with a grinder, fill and grind level once dry.
On most homes here Texas there is a raised area that has been covered with cement product for looks purposes. Hit it with the handle end of an old screwdriver and listen to insure that it is solid. You will hear a hollow sound if it is not adhered well. Remove any cement before coating if it is loose. Grinding a bevel on any removed are will make it look acceptable. Better to get it off now then have it break off later and leave an ugly spot.
Last edited:
Thanks for taking the time.