How To Install New Roofing Shingles Over Exisyting Roof

Nail the drip edge in place using your hammer and roofing nails.

How to install new roofing shingles over exisyting roof.

Leave the old valley flashing in place and install new over it. Apply roofing cement to the back. Rip cut the starter strip or starter pieces so that they butt up against the second course of existing shingles and are even with the front edge of the existing roofing. Because asphalt shingles are routinely exposed 5 in rip down the first strip the starter course so that it is 5 in.

You need to tear off the roof and install a new one. To install line the valley with underlayment secured with roofing cement. Install new shingles to the lower edge of the opening. Install new flashing metal flashing is often called drip edge along the bottom of the roof near your gutters.

Current shingles are curling or in bad shape the new shingle roof should lay flat on your old one. Remove the cover and then nail the old shingles back down again. Cut the flashing into 6 to 8 foot lengths to help prevent buckling after installation. If you nick or tear the old flashing piece then go buy a new one.

You re better off removing the old roof. Always install flashing around a chimney and other valleys where two roof planes meet as these areas are more prone to leaks if not protected. But if the current roof is curling this isn t possible. To level out an existing asphalt shingle roof rip down reduce the height of two courses of shingles as shown in the drawing below.