The shape editing tools were designed to allow for moderate slopes and in such cases variances in true thickness are trivial.
Revit roof shape editing.
A roof cannot attach to another roof and the roof cannot be a curtain roof.
However more significant slopes will increase this variance.
First activate add split line and draw the lines like below.
This also adjusts the position of the roof if the support and the roof are not aligned.
After you finish creating the roof select it.
Shape editing tools are used to create flat roof slope.
Revit will issue a warning when a slope significantly deviates from the expected thickness.
An alternative way to apply slope to a roof or floor is the shape editing tools.
On this flat slab you add one or more points and then adjust the z height of those points.
This will modify the form of the roof and allow for customized roof shapes.
Add points manually or create them automatically with split lines.
Use pick supports to split the roof element at the supporting beams.
By specifying the elevation of these points you split the surface into sub regions that can slope independently.
The shape editing tools display on the contextual tab.
These are available on flat slabs only.
Use shape editing to add internal drains to the roof built using sloped insulation.
Floors must be flat and on a horizontal plane.
Revit structure you can use shape editing tools to manipulate the surface of a flat non sloped floor or roof by defining high and low points for drainage.
In the example below we add a bunch of points and change their relative height with modify sub elements tool.
In order to enable shape editing tools the following conditions must be met.
Revit structural project 08 roof 0pen web steel joist framing and modify grid duration.
This shape editing tools will not appear if you define the roof slope.
You will see shape editing tools from in your ribbon contextual tab.