System for re-roofing asphalt shingled roofs

A method for re-roofing an existing asphalt shingled roof with a plurality of one piece metal panels, the existing asphalt shingled roof having:

• a wooden deck;
• one or more features selected from valley, hip, roof to wall, ridge and gable;
• a flashing provided for each of said one or more features, the flashing overlying the wooden deck;
• and
• asphalt shingles overlying the deck and the flashing provided for each of said one or more features, the method comprising:
• applying a roofing felt directly over the asphalt shingles;
• and
• fastening the plurality of one piece metal panels to the deck by nails that penetrate the asphalt shingles into the deck, with substantially all of the one piece metal panels in direct contact with the asphalt shingles or the roofing felt, inclusive of the shingles overlying the flashing, thereby creating a metal overlay configured such that substantially all of the asphalt shingles are overlain with the one piece metal panels and substantially all of the one piece metal panels are separated from the flashing by the shingles, the metal overlay being characterized by a plurality of horizontal seams between the one piece metal panels and a plurality of seams that extend parallel to each of said one or more features.