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.

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. Types of roof flashing. Remember to caulk the underside of the flashing with a sealant. 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.

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. Valley flashing protects the valleys where two roof planes meet. Flashing joints are lapped 6 in the direction of water flow. Position the flashing between the two roof pitches.

Place the 2 by 4 inch piece of lumber along the center of the flashing. Slide the right edge of the flashing under the highest roof pitch. A common problem area is the point where a gutter dies into an adjoining wall as the photo below illustrates. At the bottom of the roof water needs to be directed.

Now nail this first flashing at both its far ends. 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. 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. Rain should run off the roof and into the gutter.

Step 6 install the flashing.