In order to enable shape editing tools the following conditions must be met.
Revit roof drain slope.
Navigate to a suitable elevation view west elevation in the example next go to systems tab pipe draw your desired gutter downpipe run.
A roof cannot attach to another roof and the roof cannot be a curtain roof.
Your downpipe elbows should automatically generate via the revit autorouting.
Revit will issue a warning when a slope significantly deviates from the expected thickness.
If you found t.
Floors must be flat and on a horizontal plane.
In addition all flat roofs are not actually flat but also slope towards drains.
Roof floor and paving drainage systems.
Roof floor and paving drainage systems.
This video shows you how to add a split line and a point to a flat roof so that you can edit the roof to allow for drainage channels gulleys.