Before ramps are created, make sure that the heights for
what they are referencing are already set correctly.
For example, if they are going to be between two rooms on the same
floor where there is a change in the floor height, make sure
that these values are set prior to creating the ramp. The
same is true of making sure that the terrain and deck are
set correctly for an outdoor ramps.
Ramps are drawn going UP,
so they should be drawn from the lower of the two things
that they connect, such as from the lower floor height, or
from the terrain up to the deck.