Tar Paper Roofing

There are excellent tutorials on weathering a tar paper roof on YouTube.

One simple technique is to cover the roofing paper with a light coat of a contrasting color such as a medium gray. You can use spray paint or simply brush on a thin coat of acrylic paint. Lightly sand the paint vertically to reveal the black paper color underneath. For an older look, sand the bottom edge of the paper to remove a small amount of material to resemble wear.

After weathering, cut strips from the roofing paper slightly longer than the width of the roof. Dashed lines on the roof show where the roofing paper will line up.

Distribute white glue sparingly along the back of the paper by dabbing it on with your finger. Attach the strip of paper so that the bottom edge of the paper is even with the bottom edge of the roof, or slightly overlapping.

Repeat from top to bottom slightly overlapping upper layers over lower layers.

Repeat for the other roof side.

Add a final strip of roofing paper centered over the ridge at the top of the roof. This should overlap both the lower pieces of roofing paper. With the roof upside down, use a razor knife to trim the roofing paper flush with the sides of the roof. Slightly angle the blade away from the roof so you don't cut into the fascia.