Although there are many reasons that a roof can be leaking, a good place to start looking is the flashing. If done right, flashing can help protect a home from water damage, but if old or placed incorrectly, flashing can be a major source of leak problems. Anywhere multiple points on a roof meet is a prime spot for a leak to begin and well placed flashing provides an extra layer in these vulnerable locations. Areas prone to issues include skylights, vent fans, and chimneys.
To begin repairing or replacing your flashing, it is important to decide which type you will use. Most flashing is made of galvanized metal, but aluminum works just as well and is easier to bend to fit into tight spots. Flashing is designed for easy installation, and if you know how to install it, the product should protect the roof area for years to come with little or no maintenance. However, if it does begin to pose an issue it can be easily fixed with no professional experience.
Common pitched roofs have the benefit of gravity to help them direct water away from the home. They rely on a variety of elements including many under layers of material to prevent water from getting through. However, not all roofs have this benefit and in systems where flat or low sloped areas are necessary, standing water can become an issue and proper flashing is much more important.
For any roof, regardless of the type, flashing is used to direct water away from a potential leak area. It is important for the flashing to pass underneath the many layers of the roof in order to provide the best possible defense against water penetration. There are multiple types of flashing to help assist this prevention. Valley flashing protects valleys in the roof, hence the name. It is placed in areas where two sections of a roof meet and make a low point. The flashing itself is shaped in a “V” and is installed over the top of the roofing felt before the finishing materials of the roof are connected.
Vent pipe flashing fits over, or around vents or flues on the roof. This type of flashing is usually in a cylindrical shape with a very wide base to go around the vent. This is installed and intertwined with the shingles as the roof is finished. Other types of flashing are pieces that need to be welded together. These are “L” shaped metal pieces are perfect to form around areas where two major areas connect, such as a chimney or another wall on the house and the actual roof. If welded properly, the flashing will hold strong and prevent leaks for many years.