Originally posted by PhotriusPyrelus:

As a follow-up, is there any way to build supports down from flooring? Because I can't figure out how and it's kinda frustrating. =-\

You can try to mess with camera angles, but you would just have to build while looking at the underside of the floor, or whatever else you're trying to build down from. It can be quite tough in some situations.

An upcoming patch (which could be months away still) might help with this, but not sure. This is why dev commands and mods that help with building are popular.