There are three different areas that require proper roof flashing treatment:
1. Drip Edge
Drip edge is installed on the perimeter of the roof along the eaves and provides an added level of waterproofing.
- Deflects water into a rain gutter, rather than between the rain gutter and fascia, where it can damage the fascia board.
- Helps protect the roof deck from unnecessary exposure to water
- Adds support to the first row of shingles
The drip edge should be rugged and resistant to corrosion to ensure a long life.
2. Valley Flashing
Valleys naturally deal with more water run-off than the rest of the roof, and therefore require special attention.
There are two types of valley construction – closed valleys and open valleys. Closed valleys have shingles covering the valley, while open valleys have a gap between the shingles on either side, with metal in the valley.
3. Roof Penetrations
Areas where further flashing is vital:
- Roof/wall intersections
- Other roof penetrations such as vents, plumbing stacks, or dormers