Flashing Where Two Roof Lines Meet

Step flashing protects the joints between the roof deck and chimneys or dormers.

Flashing where two roof lines meet.

Now nail this first flashing at both its far ends. At the bottom of the roof water needs to be directed. Rain should run off the roof and into the gutter. A common problem area is the point where a gutter dies into an adjoining wall as the photo below illustrates.

Flashing is critical to certain areas of your roof namely the places where the roof surface meets a wall sidewalls and front walls the low points where two roof slopes meet called valleys roof protrusions bathroom kitchen vents skylights and the roof s edges rakes and eaves. This material is available with a v or w shaped profile and is placed over the top of the building felt before the roof s finishing material is installed. Valley flashing protects the valleys where two roof planes meet. The metal flashing is formed with a hook edge and cleated on 12 centers the flashing extends up the wall at least 4 the flashing extends onto the roof a minimum of 2 inches 4 inches is preferable in more severe climate areas.

Install valley battens on both ends of the roof valley then attach first flashing 3 4 inches over the roof flange and another 3 4 inches over the fascia if any is present. Slide the right edge of the flashing under the highest roof pitch. Flashing is installed to surround roof features such as vents chimneys and skylights. Flashing joints are lapped 6 in the direction of water flow.

Unless you re careful step flashing can allow water from the roof to slip behind the gutter and get behind the siding and even the housewrap. Step 6 install the flashing. Step flashing protects the gap where roofs meet walls by weaving into the roof shingles. Place the 2 by 4 inch piece of lumber along the center of the flashing.

Roof flashing is a thin material usually galvanized steel that professional roofers use to direct water away from critical areas of the roof wherever the roof plane meets a vertical surface like a wall or a dormer.