How To Install Valley Flashing On A Metal Roof

While some skylight manufacturers include flashing in their products sometimes roofing professionals have to create it or purchase it separately.

How to install valley flashing on a metal roof. Lay one and two tab shingles as you near the valley so full size shingles will run across the valley. Lap successive sheets of metal flashing a minimum of 12 inches and seal laps. That flashing is left exposed so the roof has visible lines of metal running down the valley. Then install a non corrosive metal valley flashing of 24 minimum width.

Shingle the other side of the valley the same way. I have my valley custom made with water trough to help with leaking b. Open valley shingle installation. Flashing should be installed in all of the valleys.

Roof one side of the valley running the shingles across it. The top joinery of both valleys when they meet on the same plane of roof is shown here. Open valleys have metal flashing to protect this critical area of the roof. 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.

The edge of the roof has thin metal flashing that helps water drip off the roof without damaging the home or causing a leak. Install synthetic roofing underlayment or felt paper according to manufacturer specifications and then install the first piece of valley flashing. An open valley relies on metal flashing for protection. Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles.

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. Install an underlayment centered in the roof valley. Recommended procedures of basic valley flashing installation. Installing metal flashing for your roof project is a challenging but essential step to take to ensure that the new roof remains as weatherproof and as strong as possible the following steps will explain how to install metal flashing in roof valleys.