Take a block of wood and remove what doesn't look like a horse.
As annoying as that advice can be, it is the approach I used to get the roof done of the Aylmer coal dock.
I simply took a sheet of balsa wood, traced the oval shape of the roof onto it, cut it out and then tapered and shaped the slopes with the power sander and finalized with a little hand sanding.
I'm not worried about the grain since some form of roofing material will be going on over top. Most likely tissue paper secured with paint.
The "concrete" work on the silos and hoist house is now done. Time for painting. I've primed the model with cheap and cheerful grey primer from a spray bomb and once that's dry out comes the Floquil Aged Concrete.
Once the other 2 sets of Tichy coal chutes arrive at the hobby shop, I can proceed with the discharge chutes. The beginnings of one you can see in the foreground.
Then it'll be time to build the simple roof over the hopper unloading area, a simple enough lean to structure. Again all concrete.