In this guide I will tell you how to make floating floors.
The First Way to Make Floating Floors
To make floating floors there are three ways(that I am aware of) without mods.
The first way you must first place either a wall or a pillar. Then on top of that place some triangle floors.
Then remove the wall/pillar and you have a floating floor.
The Second Way
To make floating floors this way you must first place either a wall or pillar and then place a horizontal pillar on the wall/pillar. Then on the horizontal pillar place some floors either triangle or square for this version. Then remove the wall/pillar and you have a floating floor.
Now to make a floating floor this way you must first in survival mode go to the trader and get enough reputation to buy the detail plank blueprint then research it in the research table and then open the crafting menu go to the decorations section and craft some detail planks. In creative you can just craft some in the decoration menu without going to the trader. After you have some detail planks you can place them in an incline up. You will need at least two. After you finish inclining your detail planks you can remove the one that is holding the others at the bottom. And tada you have a floating floor.
Warning you cannot place anything but detail planks on detail planks that I am aware of.
Also you can use detail planks to make an underwater raft by dragging them into the water. But watch out! Bruce can still bite you when your swiming so kill him first. Also if you walk into the water standing on the detail planks you can have unlimited air and not get killed by bruce. If you fall of beware! Bruce is coming!