In addition to these two grid systems, the model also needs a few construction grids to aid in the modeling of certain features. Construction grids are useful for modeling loads or deck areas that do not fall exactly on the framing. Construction grids will not appear in any other design module and they are not labeled. To create a construction grid:

• Select Layout > Grids > Construction Grids.
  
• With the Add Mode set to Parallel-To-Beam/Wall type 0.5 (0.15) for the distance.
• Click [Add].
• With the cursor, select any of the beams along Grid A.
• Two parallel white lines 0.5 ft from grid A5 will appear. Click on or near the west (left) line to create the new grid at that location.
• Repeat for Grid F.
• Change the Add Mode to Point-Angle
• Set the angle to 0 degrees, set the distance to 0.
  
• Click [Add].
• With the "+" cursor, click at the grid coordinates A-2 and A-3.

These construction grids will aid in laying down the different deck planes.

• Select Layout-Slab-Deck Assign.
• Select the following:
  • One-Way Slab Action,
  • 90 degree deck Orientation,
  • Noncomposite Framing System,
  • Non Composite-roof deck type from the list.
• Click [Add].
• Start at the slab edge near A-1 and move clockwise on the slab edge to A-2, F-2, F-1, and finish at A-1 taking care to trace along the slab edge where available.
• Repeat for the planes enclosed by A-2, A-3, F-3, F-2 and A-3, A-4, F-3, F-4.
• The slab should look continuous in plan and 3-D view.
  Note: You may want to try adding by whole floor to see how the sloping diaphragm is affected.

If you review the 3D view now you should be able to see the slope of the Roof.