How to Use Black Tar Paper Under Rocks

Tack 45-degree cant strips to the corners along where the plywood substrate meets the raised sidewalls of the roof, using roofing nails.

Cover the roof with a layer of rosin paper. Cut holes to fit the paper over vents and other protrusions. Secure the rosin paper with roofing nails. Overlap each section by 2 inches and run the paper over the cant strips and up the side walls.

Nail flashings around vents, pipes, chimneys and other protrusions. Paint parts of flashings that are flush with the roof with asphalt primer.

Heat asphalt in an asphalt kettle and mop a consistent coat of asphalt on top of the rosin paper. As the asphalt is applied, while it is sticky, add a layer of thick tar paper, also known as roofing felt. Overlap each section of paper by 2/3. Once finished, add three subsequent layers of asphalt and tar paper. Alternate the direction the paper is unrolled for each layer. Make sure tar paper laps over the bases of flashings and up sidewalls.

Seal seams between the roofing material and flashed parts by wrapping them in fiberglass mesh saturated with roofing cement. Once dry, paint the roofing cement with aluminum roof paint.

Paint the top layer of tar paper with asphalt and cover the roof with a 1/4-inch layer of pea gravel or crushed granite.