Autodesk 24000-000000-9860 - Revit Architecture - PC User Manual page 920

Shape edit examples
Use shape editing tools to slope a constant thickness slab or the top surface of a slab with a variable thickness
layer, to model the following:
A constant thickness slab or roof supported by sloped non-planar framing.
A variable thickness material used to slope the surface of a horizontal plane (for example, tapered
insulation).
In order to enable shape editing tools, the following conditions must be met:
Slabs must be flat and on a horizontal plane.
A roof cannot attach to another roof, and the roof cannot be a curtain roof. If either of these conditions
is not met, you cannot use the slab shape edit buttons.
NOTE If these conditions are violated later, by an edit to the element, the slab shape edit will cause an error
with a callback, allowing the user to reset the slab shape edit.
You can use the following shape edit tools on the Options Bar when you select either a slab, roof, or floor.
(Modify Sub-Elements)
882 | Chapter 12 Working with Structural Components