How to Install Roll Roofing Selvage

Cut a length of selvage roll roofing to fit along the lowest roof edge with a standard 1/4-inch overhang on each side with a utility knife. Cut away the granular half of the roll roofing and discard it.

Fasten the smooth half along the roof edge at 12-inch intervals with roofing nails into a roofing-grade solid roof deck. Nail the installation in two rows so both edges are secure.

Place a full-width selvage roll roofing length over the top of the installed half-width so that the granular section aligns with the underlying smooth roofing installation. Fasten nails at 12-inch intervals along the smooth half of the new length and set it in 4 to 5 inches from the top and center edges. Cover the lower smooth layer with asphalt-based roofing cement and a trowel, pressing the overlying roofing layer into the cement.

Align the granular edge of the next length with the edge of the granular delineation on the installed length so that you cover the smooth part of the underlying roofing. Fasten the new length in the same way as you did in Step 3, with two rows of nails and roofing cement.

Continue to install lengths of roll roofing selvage, using the same method until you complete the roof. Overlap the ends of a roll by 6 inches to maintain water tightness.