Open valley shingle installation makes use of the metal flashing sheets that need to be installed so that they overlap each other by few inches with the upper piece of sheet is resting over the bottom piece.
Pros of Open Valley Shingle Installation:
1. During its installation process, the open valley shingle utilizes the W-metal flashing, which helps in preventing the water from rushing down one roof slope and under the shingles on the other slope.
2. The installation of the open valley shingle works well with the laminated shingles and also proves to be very durable in nature.
3. While installing the open valley shingle, the exposed portion of the W-metal flashing proves to be wider at the bottom, compared to the top portion. This is done in order to help in allowing better drainage of water.
4. By installing wider and bigger valleys, there are also less chances of an ice damn to form up.
Cons of Open Valley Shingle Installation
1. While the installation process is going on, if there is too much water flowing through the channel; it might derive a risk of water pushing up under the shingles, near the edge of the W-metal flashing.
2. Another disadvantage is that the installation of this shingle requires a lot of money. It proves to be quite expensive.
3. This installation also relies on a proper shingle overlap and roof cement. It also has to be well pre-fabricated.