How To Install Valley Flashing On A Metal Roof

Open valley shingle installation.

How to install valley flashing on a metal roof.

I have my valley custom made with water trough to help with leaking b. Lap successive sheets of metal flashing a minimum of 12 inches and seal laps. W type valley flashing is more rigid for handling so it stays straight and it stops waler rushing down one side of a roof from rushing back up the other side. When installing metal valley flashing there are a few things to keep in mind from cutting metal roofing to sealing the flashing.

An open valley relies on metal flashing for protection. Some homeowners do not like the look of open valleys while others feel the metal accentuates the roof s shape particularly if copper or painted flashing. Install an underlayment centered in the roof valley. The edge of the roof has thin metal flashing that helps water drip off the roof without damaging the home or causing a leak.

Flashing should be installed in all of the valleys. Open valleys have metal flashing to protect this critical area of the roof. Lay one and two tab shingles as you near the valley so full size shingles will run across the valley. Recommended procedures of basic valley flashing installation.

Stop nailing 6 inches from the center. The top joinery of both valleys when they meet on the same plane of roof is shown here. Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles. Then install a non corrosive metal valley flashing of 24 minimum width.

That flashing is left exposed so the roof has visible lines of metal running down the valley. Metal valley trim also known as metal valley flashing is beneficial because it drains water away from the structure of your metal building which helps prevent moisture damage. Shingle the other side of the valley the same way. While some skylight manufacturers include flashing in their products sometimes roofing professionals have to create it or purchase it separately.