How To Install New Roofing Shingles Over Exisyting Roof

Install new shingles to the lower edge of the opening.

How to install new roofing shingles over exisyting 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. Install new flashing metal flashing is often called drip edge along the bottom of the roof near your gutters. Leave the old valley flashing in place and install new over it. Use a starter strip or cut pieces for a starter course.

Nail the drip edge in place using your hammer and roofing nails. 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. Cut the flashing into 6 to 8 foot lengths to help prevent buckling after installation.

To install line the valley with underlayment secured with roofing cement. If you nick or tear the old flashing piece then go buy a new one. Remove the cover and then nail the old shingles back down again. Cut the existing shingles and pry up carefully.

Because asphalt shingles are routinely exposed 5 in rip down the first strip the starter course so that it is 5 in. Apply roofing cement to the back. Attach with nails along the top edge of the strip. You need to tear off the roof and install a new one.