Spanish Tiles are the
worst
for bogging down a project. So many polygons! There is no easy way around it, except to either hide the layer in all views you absolutely don't need them on, or turn your elevations into drawings.
Neither are good solutions really. Maybe you can add them at the very last minute before publishing anything?
You know you could create a custom fill by copying and pasting from a 3D view, using the 'Look To' button on your 3D Navigation palette and a flat marquee and copying and pasting onto your floor plan and then into your new Fill Type. Then apply this as a 3D Vectorial fill to a material that you apply to a roof. As long as your have the 3D Vectorial Hatching turned on in 3D and S/E, it will show up.
It won't give that 3D look but may do a good enough job to trick 'em!
Cheers,
Link.