Capping a Roof

Measure and cut aluminum trim coil to fit over the ridgeline joint to extend 6 inches on each side of the roof. Use a measuring tape for accuracy and tin snips to cut the aluminum to size.

Center the cut aluminum over the ridgeline joint. Manually bend the aluminum to each side of the joint to shape the flashing to the angle of your roof. Fasten the flashing with galvanized roofing nails on each side of the roof at 6-inch intervals.

Position the first ridge cap at the end of the ridgeline joint that faces away from the prevailing wind direction. Fasten the cap in place with galvanized roofing nails to each side of the roof, insetting by 1-inch along the inwardly facing cap edge.

Trowel a line of roofing cement over the nail heads on the installed ridge cap. Overlap the first cap with the next ridge cap by 5 inches or according to the manufacturer's instructions. Fasten the ridge cap in the same way as you did in step 3.

Continue installing ridge caps along the ridgeline using the same procedure until you reach the other end of the roof. Apply a dab of roofing cement over the nail heads on the last cap to provide additional waterproofing to the only exposed nails on the ridgeline.