Here’s a photo of a test I’m doing… using paper medical tape, such as that sold to wrap bandages, as commercial roofing tar paper.
This photo is just an experiment. I used 1 inch wide paper tape, overlapped roughly in the middle, to produce 1/2-inch wide seams, and then painted the tape with flat black acrylic.
The 1/2-inch seam spacing is roughly correct for an HO scale building, but of course the final roof on my N scale models. I think the texture looks pretty good, though it could use another coat of paint.
Next up is another test with 1/4-inch spacing and also cutting the strips shorter so that there are some overlapping end points as well.
What do you think? How does it look?