How to Install a Corrugated Metal Patio Roof
- 1). Measure the area you will be roofing with corrugated metal. Measure the length of the roof pitch, from the bottom to a peak or to a wall if it adjoins an existing structure (like a one-story garage abutting a two-story house). Also measure the width then calculate how many panels you will need. Corrugated roofing typically comes in panels 6 feet long and 36- to 44-inches wide. Choose a style with seams that overlap and join watertight. Add at least 10 percent to the required amount to allow for overhangs and mistakes. Find the meaurement of the perimeter of your roof and divide by 6 feet (if using 6-foot lengths) to determine the number of ridge caps you will need.
- 2). Place your first panel, at the bottom of the first slope near the lip of the roof; you will work from bottom to top. Nail it into place, about 20 nails per panel, in the gullies in the panel. Some panels come with grooves so one panel slides into the next, but most have a flat half-ridge; overlap the next panel so it covers the top of a ridge and the flat portion of the next panel. Keep going until you have the entire first part of the roof covered. Move to the next course. Check your manufacturer's recommendations -- some will suggest staggering seams between courses. In that case, you will have to cut a half-panel length-wise to start the second course. Overlap the bottom of your second course about two inches over the first. Continue until you have the entire roof covered.
- 3). Install flashings and ridge caps. Flashings go against any wall that the roof abuts (like on a one-story roof abutting a two-story wall) -- one side slides up the wall (preferably under the wall covering), the other side under the roof panel. Edge caps go on the peaks, where two roof slopes meet, and on the bottom edge of the first panels, curving over the lip of the roof so water cannot get up under the roofing. You may want to add roof caulking in any places where it would appear water could get in.
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