To Draw a special Floating Wall including Split or Overhead or Floating or Internal Thermal Mass Walls you use the New Wall button in the Left Toolbar or the keyboard shortcut ⌨ N
Floating Walls needs to begin within their parent Zone, where they finish is not important. Regardless of where they are moved to, a Special Wall always remains a part of the original parent Zone.
The first 🖱 Left-Click will be the left edge of the Wall considering the wall facing outwards
The second 🖱 Left-Click finishes the Wall.
Hold ⌨ Shift for straight lines
🖱 Right-Click to reset points, or enter Manual Wall length by typing, as per the other Drawing Modes.