How Much Overlap On Metal Roofing

Any end laps must be supported by a suitable purlin.

How much overlap on metal roofing.

How to overlap metal roofing. Install the roofing screws vertically along each rib in the panel. Overlapping anti condensation lined sheets. As a first line of defense against water damage it is important that the metal roof overlap be implemented correctly.

For example if the measured length is 19 feet 10 inches and an additional overlap of 6 inches is required at both ends the final figure will be 21 feet 19 feet 10 inches plus 6 inches times 2. The panels overlap allowing water to flow from one panel to the next without being able to penetrate the area under the roofing panel. When laying the metal panels on the roof the overlap ridge of the new panel should straddle the underlap ridge of the panel before it. How to overlap corrugated metal roofing.

Install metal panels or shingles align the first metal roofing panel so that it overlaps the edging by 1 2 to 3 4 of an inch and is square to the roof line. Apply side lap sealant if the pitch of your roof is 2 12 or less. If end laps are required you should allow 300mm minimum overlap sealed with butyl sealant tape 10mm from the edge of each overlapping sheet as well as in the middle of the overlap. Be sure the larger edge is laid so that the small edge of the next panel will overlap it.

Secure the sheets into place with screws. If you re installing a metal roof on a home without gutters you can overhang the panels by twice that amount. Once the first sheet is in place you need to install the remainder of the lowest row of corrugated metal roofing. The sheets should overlap by at least four inches add a bead of caulk where they overlap and at the other end of the building ensure there s an overhang of two inches.