Rather than start a new thread I thought that I would add a section here on the corrugated and to resurrect this thread a little.
First the Asbestos was a printed texture from the Mayang's Textures site, this was a few years ago and I do not know if that site is still up.
next it was cut into the sheet size and run through the crimper
then glued onto the substrate(corrugated cardboard) of the building.
Now for the rusty corrugated used on the bridge.
first the cover-stock was painted with a course brush with some old Pelican Ink.
Then before it was dry different browns ochres and orange Rembrant pastel chalks liberally applied, I kept the direction the same for all the applications. and dried coffee grounds were rubbed into the damp card
the card was flipped over after it was dry and wire brushed by hand. then cut into sheet sizes before running through the crimper I seem to recall having to experiment a little to get the correct width to wind up with the correct size for the finished sheets.
I made more than i needed so I could select the ones that had the best look(totally subjective of course)
next I touched up the edges with a reddish brown chalk.
Lined them up and stuck them to the roof of the bridge with carpenters yellow glue using a tooth pick.
I hope this helps, it was a while ago that I did this, and now I want to get back to working on the layout, I need to get a couple of other projects out of the way first but all the parts are still there I do have a little remedial work to do on one edge of the layout a touch of moisture being the culprit for the damage.