A roof is a structure that covers the uppermost part of a building. The function of a roof is to protect the building and its contents from the effects of weather. The primary function of a roof is to protect the building and its contents from rain.
In Revit Architecture, you can create roof structure using tools provided in the Roof drop-down in the Build panel of Architecture tab.
Roof by Footprint
The roof footprint is a two dimensional sketch of the perimeter of a roof. In Autodesk Revit, you can create a roof footprint by drawing lines or picking walls that will define the perimeter of the roof to be created. If you are in the Level 1 and wanted to create roof on second floor then on choosing the Roof by Footprint tool; the Lower Level Notice dialog box is displayed prompting you to create a roof on second floor. Choose Yes; the Modify | Create Roof Footprint tab is displayed. Now, create roof using the sketching tools, as shown in Figure 1. While creating, you will notice a triangle on each line which represents slope. If wanted to remove slope from any plane just select that plane and clear the Define Slope check box from the Options Bar. Now, choose the Finish Edit Mode tool to complete sketching of roof.
Figure 1 Sketched roof
Use the Default 3D tool to view the model in 3D view, as shown in Figure 2.
Figure 2 3D view of roof