Galvanized Metal Roofing Installation

Measure the roof to determine the number of panels needed. Standard panels are 26 inches wide, designed to cover 24 inches of roof while allowing for the overlap of panel edges. Lengths vary from 8 to 20 feet. Get panels that will cover the roof with as few panels as possible; try to buy panels long enough to cover the roof from peak to edge.

Set the first panel in place at the bottom of one edge of the roof. Align it with the edge of the roof with a slight overhang and at the bottom of the roof, also with a slight overhang. Fasten it with galvanized screws and plastic washer caps driven in with a screw gun to the roof sheathing. Put the first screw at least one valley inside the roof side. Add other screws about a foot apart in width and into joists or sheathing, typically about 24 inches apart. Drive the screws until the washer is flush with the panel.

Place the last screws far enough inside the panel to allow for an overlap, typically one ridge and one valley. Set the next panel in place with the proper overlap and fasten it with screws through both that panel and the underlying one. Work across the roof, securing panels both horizontally and vertically.

Start a second row of panels, if needed, by cutting one panel in half lengthwise with tin snips so the seams do not align. Overlap that panel over the bottom row at least 6 inches and fasten it through both panels. Work until both sides of the roof are covered with panels.

Install ridge caps over the peak of the roof. Get these formed to fit the style of corrugated panel you used. Install these with screws and washer caps. Add edge caps, also formed for the specific roofing panels, around all edges of the roof, sides and bottom, to keep water from getting under the metal panels and onto the wooden roof sheathing.