All roofs require some sort of flashing, which is used to cover the place where two parts of a roof join together. It prevents water from getting underneath the roofing material and cause damage to the roof deck. However, you may not be aware that there are different kinds of roof flashing that are used by roofing companies. Here is what you need to know about each type of flashing material.
Valley Flashing Material
Your roof valley is where two parts of the roof join together into a v shape, and carry rain water down the surface to your gutters. This point where the roof joins requires flashing, since a lot of water will run down this part of the roof over the years. Leaving the roofing material on its own in this part of the roof will not be enough to provide protection. It's common to install flashing beneath the shingles on this part of the roof. This is because you won't have to replace the flashing when doing roof repair or replacement.
There are likely many vents that protrude from your roof, and they need to go through the roofing material to reach the outside. These vents require a special kind of flashing that matches the shape of the vent and slides over it. The flashing functions almost as an oddly shaped shingle, since it goes on top of the roofing material so that water rolls off the flashing material and onto the roof itself.
Drip Edge Flashing
There are edges along your roof and the eves that require special flashing material known as drip edge flashing. The material extends away from your roof and prevents the water from finding its way between your home's interior and the roof fascia boards. The flashing material is placed around your entire roof and is underneath the bottom row of shingles. Much like the valley flashing material, drip edge flashing doesn't need to be removed when performing roof repair or replacement.
The material that wraps around an edge of dormers or chimneys is called step flashing material. It's designed to lay flat against the roof and the surface coming out from a roof at a 90 degree angle. This flashing material is placed on top of the shingles and is often replaced compare to other forms of flashing material.
If you happen to have any concerns or questions about roof flashing material, reach out to a local roofing contractor.