If its an issue of forcing certain information in to a wall tag because thats how you did it previously youre going to struggle getting revit to do what you want.
Revit roof layers.
Select roof by footprint for the architectural tab.
The add in analyzes all layered structures in an autodesk revit project looking for material names and layer widths thicknesses.
Roof construction in revit.
On the properties palette click edit type.
Materials widths and material layers with widths can be written into multiline type parameters of all six layered categories ceilings floors site pads roofs structural foundations and walls.
Select the floor or roof.
There are two types of information in a wall in revit.
In the edit assembly dialog specify the material for layers and the thickness of those layers.
Then you tag the individual layers of the wall and not the wall itself.
The variable thickness parameter column will contain empty check boxes next to layers where variable thickness can be enabled.
You should be left with a lean to roof with just a single fall similar to the following.
Draw your roof boundary.
Materials widths and material layers with widths are written into multi line type parameters of all six layered categories ceilings floors site pads roofs structural foundations and walls.
Select all but one boundary and turn off defines slope parameter.
Https youtu be pl5jqj8btfc wall layers in revit tutorial.
The best way to model a lean to roof in revit is to use the roof by footprint tool.