Things You'll Need
Metal roof paneling and trim
If the metal roof on your storage shed has begun to show serious signs of rust, it's time to replace it. Fortunately, since metal roofs are built out of large panels rather than much smaller shingles, removing one is considerably easier than removing an asphalt roof. Once you've taken the old roof off, installing the new one is almost as simple — you should be able to replace your shed's roof in only a couple afternoons.
Unscrew the trim on the existing roof and remove each piece of metal trim. Remove the screws from the topmost roofing panel and slide it off, continuing on to the next lowest panel until you've stripped the entire roof off the shed.
Lay the first panel of the new metal roof in the lower downwind corner and secure it to the purlins, driving one screw on either side of each ridge in the panel. Place the next panel just above the first, overlapping it by 6 inches, and continue until the paneling reaches the ridge.
Run a strip of butyl tape down the inside edge of the column of panels and install the next column, starting near the eaves and working up to the ridge as before. Keep laying panels, one column at a time, until you reach the upwind edge of the roof. If your shed has a gable roof, install the paneling on the other side of the roof the same way as the first.
Install the rake and ridge trim, hooking it over the edge of the panels and screwing it in place. Overlap each piece of trim by 4 inches for best results.