How do we model standing seam metal roof in Revit?

I guess it depends on how specific you want it to look. I use a material called Roofing - Metal Standing Seam that I set to use an ootb Relief Pattern called Standing.Seam.png to control the Render Appearance, and a simple Model Surface Pattern called Standing Seam - 16" (etc.) to control it's graphics for Plans and Elevations, and it works great. If you want more detail, use Fascia objects with defined Profiles to use for the Ridge vent, hips, end dams, etc. If you actually want modeled ribs, you'll need to create a custom family or use a workaround (I've heard of people using curtain walls for this, but to me, that's not the right approach). I personally don't model the ribs.