Let's start with one simple rule for people who want to install metal roofing.

If you can't easily walk across the roof because it's too steep, call a professional. Now that the rule is out of the way, if you have a building that needs a metal roof but the professional bids are too high, here's how to install it.

First the proper tools are needed. The list is a measuring tape, a chalk line with plenty of chalk, a good drill, a good extension ladder and a safe step ladder, ½ pound of ¼ inch roofing nails, metal roofing screws, metal snips, and to hold the nails and screws a nail bag.

Measure the roof's height and add the desired overhang, generally two to four inches. Make accurate measurements keeping in mind the handy man's mantra “measure twice, cut once.” Then measure the roof's length and height on both sides to figure out how much metal edging to add. Bring these measurements to a local roofing supply company. They will tell you how much roofing to purchase. Keep in mind that between 3 and 6 inches of unblocked air flow is needed between layers.

Although it isn't necessary to remove the old roof before laying down a metal roof, it is best. Use a pitch fork, roofing shovel, or roofing pliers to remove old shingles . Then lay down 30 pound tar paper to serve as the base for the new roof. If there's only one layer of shingles on the old roof, lay down 1”x4”x building length pine wood boards screwed onto the old shingles. Apply metal roof edging once the roof is prepared.

Start placing the metal sheets running from top to bottom. They are screwed into the wood slats, using a screw every two feet on both sides of the sheet. Each sheet must overlap the last. When you reach the edge cut the last metal sheet so it's just past the edge of the roof.

Once the sheets are applied to both sides of the roof it's time to apply the metal trim along the sides of the roof at the edge. The trim also goes on the peak, first scoring it in the middle so it can be bent over the peak.

That covers installing the tin barn roof type of metal roof. Other types of metal roofs require different methods for installation. But those can be tackled equally as well by a do it yourself person who wants to install metal roofing.