I received at least three requests from the users "how to create the flat roof and slab with the negative sloping". They work with big plant buildings and they have to create difficult flat slabs and roofs with difficult negative sloping for drainage and drain.

Yes, we have the Modify tools for the slabs and solids, but there we can't add the angle or rise:run or percent of negative slope, and it's a very complicated way if you need to change something. Almost every time you should delete your modification and work from the scratch.