If you do any repairs or maintenance on you car in your personal garage you have probably ran into the problem of some fluids leaking on the floor and making it dangerously slick. You know, maybe you spilt some oil out of your catch basin or maybe the oil filter you took off turned over and spilled. Either way, you now know how dangerous this can be if you step on the spill. You need an anti-slip topping on the floor for better traction. The best garage floor surface for this application is an industrial sand grit.
Some people will try to apply a standard paint to their floor and then spread out sea sand as a way to increase the footing. This doesn’t work for two reasons. First, sea sand usually has a very high salt content. Salt is very corrosive and is not good for concrete floors. Many people think that concrete is nearly indestructible but that is not true. Salt can cause havoc with concrete. If you have salt on the floor and then you drive in with water dripping off your car from the rain or snow melt then you will get this salt/water mixture seeping into any cracks in the floor. If you have any rebar or steel matting in the floor slab for strength then it will start to rust. When steel rusts it expands with great force and this can actually break the concrete up and allow even more damage.
The second reason that sea salt is not great for an anti-slip additive is the size of the grains. Industrial grits come in many different sizes and you can choose the one you like for your application. Heavy grit for more traction or a lighter grit if you are just worried about the floor being slick from water, not petroleum products.
If you are going to apply a garage floor paint then use an industrial grit for traction.