Once again select the wall first 1.
Revit roof secrets.
Roof by footprint can be used for both flat and sloped pitched roofs.
But i m not really sure if this is a best practice.
In the option bar make sure defines slope is activated for boundary lines.
I believe this tools are not design for this purpose.
Revit then makes the wall meet the underside of the roof correctly.
Using shape editing tools.
We can use the same attach top base tool to tidy up this junction.
Then choose attach top base 2 and finally select the roof 3.
Please like this video.
2 activate slope to create a sloped roof want to create a sloped roof.
Discover free revit bim objects for roofs.
To turn a sloped roof into a flat roof select all roof boundaries purple lines and uncheck defines slope in the option bar.
This is the easiest way to do it.
For creating complex roof it might be easier if you create separate roof then use join roof tool to join them later.