Yes, you absolutely need to prepare the concrete in your garage before applying a new floor system. Even if your garage is brand new. You can even prep the floor in a carport or a Portable Garage made from wood. Good preparation is critical to a quality garage floor. There are many reasons a coating will mess up. The key is preparation, preparation, preparation.
If your concrete is new, you must wait at least 28 days before applying anything. This is the amount of time concrete takes to reach its maximum hardness and strength, and be free of moisture. If your concrete is too wet, it will not hold a coating. Check your garage floor to make sure it is not holding moisture.
If there is an existing sealer, coating, or any other agent on your floor, it will need to be removed. Additionally, if your concrete, is soft or chalky, the new floor coating may not adhere properly. For solve these issues, careful grinding must be done. And it must be done well. No short cuts.
If your concrete has cracks, they should be repaired. Crack filler is used to fill cracks. If the crack is large, you may want to grind it to be twice the size that it is, and then fill it in. Remember, if your concrete cracks under your newly coated floors, your new coating will probably crack as well.
As for the expansion joints, they are there for a reason – to prevent cracking of the concrete. So, we prefer to leave them. But if you have a good reason for wanting them gone, let us know. We have ways to do this properly.
Don’t forget, you are planning to spend your hard-earned money on a new flooring system; you should be sure that the preparation of the existing floor is done right. Your new floor will only last as long, or look as good as the surface that is under it. Make sure your new floor has a solid, clean foundation.