Drip edge is a metal flashing that is installed at the edges of a roof to help control the flow of water away from the fascia and to protect the underlying roofing components. It is usually shaped like an "L" and is installed at the edge of the roof, overhanging the sides of the roof. Drip edges serve a vital function by directing water away from the fascia and into the gutter, preventing water from running down the fascia and onto or into the soffit cavity. Without a drip edge, water may end up beneath the shingles and may cause damage to various parts of the home. Drip edges are required by most building codes across North America to protect homes from damage. The key benefits of drip edges include:

• Directing water away from the fascia and preventing water from rotting the fascia over time.
• Protecting the edge of the decking due to water penetration during driving rains.
• Keeping water, especially wind-driven water, from your roof foundation.
• Keeping out insects and small animals that could harm your decking, roof, or get into your attic.

Drip edges are usually constructed from corrosion-resistant or galvanized metal, such as galvanized steel, aluminum, or copper. There are several different types of drip edge, constructed in different shapes depending on the type of roof they are intended for.