Winter water
Does a coated floor make a garage wetter in winter?
It looks wetter because the snow melting off a vehicle stays on the surface instead of soaking into the slab, which is the floor doing what it is for.
The short version
- Snow comes off a vehicle and melts in a warm garage whatever the floor is.
- Bare concrete takes the meltwater in, and that is the process that pits a slab.
- A coated floor holds it on the surface, so you can see it and move it.
- A rubber squeegee pushes it to the overhead door or the floor drain.
- A slab with no slope and no drain holds a puddle. That is the concrete, not the coating.
Why the floor looks wetter
A vehicle that has been out in a snow comes home with it packed into the wheel wells and along the rockers, and in a garage that is above freezing all of it melts onto the floor. That happens whatever is under the tires. What changes is where the water goes next.
Bare concrete drinks it. The puddle soaks in, the floor looks dry again, and the water is now sitting in the top of the slab waiting for the next cold night to freeze it. That is the process that pits a garage floor, and it is quiet while it is doing it.
A coated floor has nowhere to put it. The film is not absorbent, so the melt stays on the surface where you can see it, and the floor looks wetter than the bare slab ever did. It is the same water. It is being held where somebody can push it out instead of soaking into the concrete.
What people do about it
A rubber squeegee on a pole is the common answer. Push the water toward the overhead door or the floor drain and the floor is clear before you go inside. Most owners end up with one hanging by the door and stop thinking about it.
A containment mat is the other one. It is a mat with a raised lip that goes under a vehicle, and the snow melts onto the mat and stays in it rather than running out across the floor. It is worth the money in a garage you also work in, or where the slope runs the wrong way.
Where the water ends up
Where it ends up is set by the slope of the slab, and that slope was poured long before anybody coated it. Most garage floors are poured to drain out toward the overhead door. On those you push the water a few feet and gravity takes it from there, which is why owners of those garages never think about any of this.
Some are poured to a floor drain instead, which works the same way with less pushing. And some are flat, or run slightly back toward the house, and those hold a puddle in the middle of the room. A coating does not change any of that. What it changes is that the water is on top where you can see it and get it out.