Types of Roof Flashing and Their Applications

Metal roofing is a popular choice for its durability, longevity, and aesthetic appeal. To ensure a watertight and structurally sound metal roofing system, the incorporation of flashing is crucial. Flashing serves as a protective barrier, preventing water from infiltrating vulnerable areas and causing damage. In this article, we’ll delve into the different types of metal roof flashing and their applications.

1. Ridge Flashing:

Application: Ridge flashing is installed at the highest point of the roof where two slopes meet, known as the ridge. It helps to prevent water from penetrating the roof along this vulnerable juncture.

Materials: Ridge flashing is typically made of metal, such as aluminum or galvanized steel, to match the roofing material.

Design: The design often involves a V-shaped configuration that sits atop the ridge, providing a barrier against water infiltration.

2. Valley Flashing:

Application: Valleys are the areas where two roof slopes intersect, forming a channel for water runoff. Valley flashing is crucial in directing water away and preventing leaks.

Materials: Similar to ridge flashing, valley flashing is commonly made from metals like aluminum or steel.

Design: It is designed to fit into the valley, creating a water-resistant barrier and protecting this critical area from potential leaks.

3. Step Flashing:

Application: Step flashing is used in areas where the roof meets a vertical surface, such as a wall or chimney. It provides protection at each “step” or course of roofing material.

Materials: Step flashing is typically composed of metal, and it is often paired with other waterproofing materials like roofing felt.

Design: The design involves individual L-shaped pieces that are layered with roofing material and the vertical surface, creating a step-like pattern.

4. Chimney Flashing:

Application: Chimney flashing is employed around the base of chimneys to prevent water infiltration at this complex intersection.

Materials: Metal chimney flashing can be made of lead, copper, or aluminum due to their malleability and corrosion resistance.

Design: It usually involves a base flashing at the bottom, step flashing along the sides, and counterflashing embedded into the chimney mortar joints.

5. Drip Edge Flashing:

Application: Drip edge flashing is installed along the edges of the roof to direct water away from the fascia and prevent it from seeping under the roofing material.

Materials: It is commonly made from aluminum, although galvanized steel is also used.

Design: Drip edge flashing features a slight outward bend, encouraging water to drip away from the roof rather than collecting along the edges.

6. Eave Flashing:

Application: Eave flashing is positioned along the eaves to prevent water from entering the building and causing damage to the underlying structure.

Materials: Similar to drip edge flashing, eave flashing is often made of aluminum or galvanized steel.

Design: It is designed to provide a seal at the edge of the roof, protecting against wind-driven rain and ice dams.

In conclusion, the proper selection and installation of metal roof flashing are essential for the long-term performance and integrity of a metal roofing system. Each type of flashing plays a unique role in safeguarding vulnerable areas, ensuring that water is directed away from potential entry points. Whether it’s ridge, valley, step, chimney, drip edge, or eave flashing, the right combination will contribute to a watertight and durable metal roofing solution.