Been watching great tut https://www.youtube.com/watch?v=V3wghbZ-Vh4&t=1330s but still making my way through. At the moment slightly confused how to combine a roughness map with fresnel ? I’ve ended up with fresnel masking the roughness rather than a combination.
Principle node (only available in the latest experimental blender build atm), or you can google Andrew Price PBR shaders. he has one for dialectic materials and one for metallic.
Still waiting for the official release. 
Eevee too.
Take a look two threads down 
The second sticky ?
jesus crist you are lazy…
i told you the second option, download these…
i found them for you.
Thanks. Sorry, just a little slow. :-p