How To Install Valley Flashing To An Existing Roof

The three methods to shingle a roof valley.

How to install valley flashing to an existing roof.

Then install a non corrosive metal valley flashing of 24 minimum width. Before you apply the flashing you ll need to lay down a waterproof membrane. Lap successive sheets of metal flashing a minimum of 12 inches and seal laps. Install an underlayment centered in the roof valley.

Install synthetic roofing underlayment or felt paper according to manufacturer specifications and then install the first piece of valley flashing. 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 the underlayment as directed by the manufacturer then set the valley flashing on top of it. This recommendation includes iko s premium shingles.

Many roofers cut the shingles across because they say it s safer. Iko recommends that you install architectural shingles with the open valley method for the best roof performance. Flashing can be purchased in pre formed styles to help you install it more easily and these include. When deciding how to shingle a roof valley you will need to consider your materials the climate and the desired look of the roof.

Leave the old valley flashing in place and install new over it. Step flashing built to protect joints between roofs chimneys and other objects like skylights this flashing steps up above the shingles and attaches to the object providing comprehensive water protection. The top joinery of both valleys when they meet on the same plane of roof is shown here. Vent pipe flashing as the name implies this flashing is usually.

Along the rakes install a new j channel drip edge which wraps around the old rake flashing and starter courses. Especially if you live in an area that gets a lot of snow and ice. To level out an existing asphalt shingle roof rip down reduce the height of two courses of shingles as shown in the drawing below. Recommended procedures of basic valley flashing installation.

In this video i show you how i do the valleys on a shingle roof. I have my valley custom made with water trough to help with leaking b.