Should baseboard trim be in contact with the flooring?
Best practice is that something at the lower edge of the wall should come down on top of the finished floor surface. If you install baseboard alone then that should be installed last over the finished floor. On the other hand if the plan is to install a base board plus base shoe then you could choose to install the baseboard first and then run the finished flooring material up to the baseboard and cover the final installation with the base shoe.
Since many modern choices of flooring used these days are typically installed with a 1/4&quot; to 3/8&quot; gap of the finished flooring from the walls this can be difficult to cover adequately with just a base shoe as the material is fairly thin. In these cases it would be strongly recommended to install both the baseboard (and baseshoe if desired) after the finished floor surface is installed.