Not really a problem if you have a garage or basement with a drain. If your garage or basement is always damp, the tiles is above the wet concrete and has drain channels underneath for the water to flow. You can also unsnap the floor tiles and clean underneath.
Plastic is also impervious to common garage chemicals such as oil, gas, brake fluid, and etc. It can take the standard floor jacks and jack stands if it does not have sharp edges on it. The only thing that will not work on it is high heat such as the sparks from a welder.
The rised ribbs on it are for traction and have a patent on its design. The only thing I recommend for a working garage is to NOT use the white tiles as it is hard to keep clean.
The tiles are available with bumpstops and ramp-edge pieces for the garage door openings.
