The wet effect is a mesh with colour, transparency and reflection properties applied. It is squashed up at the beginning and then scaled out across the floor as it progresses.
The lines on the floor are a jpg applied as a decal
regards
simon
hmmm... as an experiment, I'd change the mesh of the floor to be more dense. Is it just one patch? Try 4x4. and reapply the decal. Whatever it is... change it to a different mesh and see what happens.
Of course make sure the "wet" mesh isn't falling below the floor mesh.