How to Install a Metal Roof on an Existing House

Wear gloves, eye protection and a safety harness when working on the roof. Brace the ladder carefully and make sure it is solidly placed before attempting to climb onto the roof.

Remove the old roofing from the entire surface of the roof, if you are choosing to not cover old shingles. Old shingles can be pried off with a roofing spade and disposed of according to local regulations. Your county may have laws regarding the disposal of old roofing materials, so be sure to check before dumping them.

Sweep the surface of the roof so that it is free of any debris. Remove any screws or nails that are sticking up so that the surface is smooth.

Unroll an insulated vapor barrier across the roof one section at a time. Be sure the vapor barrier side is against the roof. Nail it in place with galvanized nails. It can either be attached to the roofing deck or to the trusses.

Place the closure strips along the eaves and fasten them in place with galvanized nails. Some closure strips have adhesive on them to help hold them in place. Seal the upper edges of the strips with roof caulking to keep moisture out.

Lay the corrugated panels in place so that they fit snugly over the closure strips and use screws with attached washers to secure the panels. Start with the row at the lowest level of the roof and complete it before moving to the next row. Overlap the sides of the panels as you place them, applying a line of caulking between them before you fasten each one in place. Also apply caulking between the rows so that water can’t get in around the ends of the panels.

Place the ridge panel on the ridge of the roof after all of the metal panels are in place. Apply caulking where it touches the corrugated panels. Use screws with washers to hold the ridge panel in place and complete the roof.