How to Place Roof Flashing

Valley Flashing

• 1

  Position one piece of valley flashing into the portion of the valley that meets the eves, ensuring that the “V” aligns with the crease in the valley.

• 2

  Drive a roofing nail every 12 inches along the edges of the flashing piece with a roofing hammer.

• 3

  Install the next piece of flashing in the same manner. The bottom of this new flashing piece must overlap the top of the first-installed piece by at least eight inches.

• 4

  Continue installing flashing pieces until the flashing reaches the ridge of the roof.

• 5

  Bend the excess flashing material over the ridge of the roof until the excess flashing lies flat against the opposite side of the roof and nail the excess flashing into the roof.

• 6

  Apply roofing cement over each nail head and along both sides of all flashing pieces.

Step Flashing

• 7

  Cut flashing material into 10-inch wide strips with aviation snips.

• 8

  Place two boards between the jaws of a bench vice, then insert half of one flashing strip between the boards. Close the vice jaws until the flashing is held securely.

• 9

  Tap the upper-half of the flashing piece with a rubber mallet to bend the flashing to a 90-degree angle, then remove the flashing from the vice.

• 10

  Position the bent flashing piece over the upper half of the roofing shingle located at the bottom of the area you intend to flash.

• 11

  Drive a roofing nail into the vertical portion of the flashing with a roofing hammer.

• 12

  Install the next course of shingles, moving up the roof, with the shingle completely covering the bottom portion of the installed flashing piece.

• 13

  Repeat Steps 2 through 6 until all of the flashing pieces are installed.